Why can't older Androids receive new OS updates?

The answer is that android updates are provided by either the manufacturer (for an unbranded, off-contract model) or the carrier (for a model sold by the carrier and where the carrier has modified the software - even if that modification consists only of adding bloat apps). Only Nexus devices have the updates provided by Google.

So, whoever provides the updates has to decide not just which devices are technically capable of receiving them but which ones it makes sense commercially to put the effort in to provide an update for. Remember that Android needs to be customised, built, tested for every device, so it costs staff time and hence money to do this. So at some point, for various reasons, the manufacturer might decide not to support further updates for a particular device, or even if they do the carrier may decide it's not worth their doing so (which happens: you get cases where the stock international version of a handset gets updates but some particular carrier's version does not).

Sometimes older models may get the update but not as quickly as the newer ones, which probably means that the development team only turned to them after the newer and more commercially important devices were done.

Bottom line: though in some cases it's hardware, it's often a commercial decision, but not by Google and not necessarily even by the manufacturer.

Before anyone makes the inevitable comparison with Apple, they don't have many devices to support and don't allow network customisation. But even so they stop providing updates on a fixed timetable rather than necessarily when the device cannot support them, and also leave out features in the older devices, only some of which are hardware related (as in some cases people with jailbroken iPhones have enabled features which Apple claimed the hardware doesn't support). So again, we're talking commercial decisions here.

 

Just as an addition to the informative answers already posted, are you aware that the 1st-gen Nexus 7 definitely will get updated to Android 5 Lollipop, and possibly even more after that? So will the 2 year old Nexus 4. So the situation is maybe not as dire as you might think, especially if you stay with devices with less manufacturer customization.

 

Despite what it may seem, Samsung has actually only released one flagship Galaxy S and one Galaxy Note a year. They do many other Galaxy phones as well, such as the Ace series and Mega series, but these are phones in different price, feature and size ranges, to suit various pocket, customer and market requirements. Not all of Samsung's phones are available in any one country. Different Samsung phones can be released in different regions, e.g. the Galaxy Trend and Galaxy Young are only available in Asia, countries like China and India.

To be frank most people don't do that. They tend to keep phones for maybe two years, because that's the length of their carrier contracts, especially in western markets like the US. And Samsung usually does support their devices with updates for a length of two years. Same with other major manufacturers as well, like HTC and LG.

 

Because, otherwise you will not buy the latest devices.

 

The better OEMs for support seem to be Motorola and HTC. Samsung supports their devices for a while too, but they take their damn time to push them out. LG seems to be on the bad side of upgrades...as in you buy a phone and it's likely you may not see an update. I remember when KitKat came out and they refused to update the Optimus G, which was only 1 year old at that point(and the Nexus 4 was based off of it).

 

Actually, if i'm not mistaken, it's Notes that get once-a-year upgrades, while the S-series get one every six months. the S5 came out a mere few months after the S4 launched.

As for the issue of older devices getting newer versions of the OS, i would bet on the same reasons it's a bad idea to run Windows 98SE on an i486/33. it can be done, but the results are not pretty. Does anyone remember when the iPhone 4 got iOS 7 and then complained about lag, battery life and so on?

 

While it does seem like Samsung releases a new flagship every couple months, I checked the release dates and the S line is really once every year.

S1 - June 2010
S2 - May 2011
S3 - May 2012
S4 - April 2013
S5 - April 2014

I have an S1 on my shelf running CM 11. It's still pretty damn laggy. So there is a point when it doesn't make sense to update devices. Especially given that most people are on a 2 year contract plan and are just going to replace the device anyway.

 

Then my case is simply my town being late to the game on everything. i got my S4 just after it launched (here--around July 2014) and i saw the launch of the S5 just after that (around September 2014). the Note 4 has yet to arrive as is the iPhone 6. the demos are about it. i am sure both have launched though everywhere else.

I got the LG G3 just after it appeared on the Best Buy shelves--last month. i know that particular phone has been out a while now. but we just got it.

 

I can confirm that the Note 4 and iPhone 6 have launched in Inner Mongolia and Mongolia. I've seen them here, and my friend in Ulan Bator says he's seen them as well. So I guess that leaves just Pyongyang, North Korea and Owensboro, United States as not having them yet.

 

Note 4 and iPhone 6 are out in the Philippines and Singapore as well.

Anyway, I am using a Note 2 which is running official Samsung Kitkat, and Samsung already announced that it will receive Lollipop via official update channels. Likely it's the last update it will get. Typically, the Notes and S series from Samsung gets an update or two after their 2year younger revisions get released. The Note 1 got an update after the Note 3 as it's last IIRC. Of course at this point it will depend on your carrier if you'll get an update or not.

 

Ouch, Nick. Looks like KY is behind Mongolia .

I come from a small town too, so I know what it's like to have to get everything from elsewhere. We did have reliable high speed internet though, until last year when the local ISP got bought out by a regional cable company who turned it all to garbage.

Now I'm in the city with a crappy internet connection

 

Singapore can be like Hong Kong, always seems to get the latest tech very quickly. In fact the only time I've seen a Google Glass for real was in HK. And the internet is usually very fast and reliable as well.

 

due to the anti-tech anti-progress mindset of people around here (they still refuse to even bother with cleaner energy and hold to coal mining as if it were life and death) there are a lot of things we never even saw period. inductive wireless charging mats? nope. NFC? nope. QR Codes? dying and all but gone from public view. the most popular phone is an iPhone, albeit a few generations behind. the younger set and children tend to have Samsung or some off-brand cheap Android phone. a few adults have S3's or S4's.

 

In a nutshell we'd love to blame it on hardware limitations and leave it at that. However we all know in technology its upgrade or perish...
A phones viability commercially is about a fiscal quarter.(3 months or so) It'd be very difficult for the average consumer to justify shelling out $500 plus on the "next big thing" if their 90 day old phone was getting updated to the latest software. So that being said most tech junkies will get the latest hardware to have the latest software...which is the service providers and manufacturers intent. Luckily we have a wonderful development community that keep phones current and viable long past their intended shelf life.

 

Yep. Or if you insist on having 3 year factory updates, switch to Apple and enjoy your phone slowing down and getting left behind in features despite getting updates. Ask any iPhone 4 user that's on iOS 7.