I have an opinion about why some device updates come much later than promised, but it's not a popular opinion.
Most popular opinions are the ones which have embedded in them some notion of a conspiracy to frustrate or inflict pain on device/carrier users, or to cause users to spend more money by purchasing another device, as if people frustrated with Samsung will go back to Samsung for their next phone.
The biggest clue is that these long waits cause many users to burn out and start looking around at other manufacturers and other carriers. That is certainly not a strategy of Samsung or Verizon, to have their money flow switch direction away from them.
That leaves mistakes and incompetence, probably at more than one level, as the reason for the delays. They can't help it, they're trying; they don't want to lose us, but they're failing at bringing updates to some of their devices in a timely, efficient manner because the techs making the update software are having problems that they can't resolve quickly, over and over again. We've seen this in automobile recalls, and in other areas where consumers complain. I really think it's that simple.
Your reasoning has merit, and I think you're right about Samsung's point of view, but right now the only thing on Verizon's mind is the damn iPhone. I've pointed out numerous signs that offer strong evidence that this is the case.
Granted, to say it's the "only" thing on Verizon's mind is probably an exaggeration. But it's definitely more on the forefront than releasing other android phones in a timely manner or updating the ones that are out there now. They may deny this, but their efforts are clear.
What other smartphone have they gone to such an extent do sell? What other smartphone manufacturer have the kissed as much butt for?
None.
They were willing to let people return a competing smartphone MONTHS after purchase for $200 credit towards the new iPhone. This is well out of their normal return policy, and mysteriously WITHOUT the $35 restocking fee. What other smartphone have they announced A HARD RELEASE DATE so far in advance for? Been with Verizon for a decade, and I can't recall any other time.
And for the final question, I dare you to find me another modern, newly released smartphone with as little of Verizon's bloat on it right now a the iPhone has. Even the Thunderbolt has a good sampling of crap on it. I've seen you on the TB forums.
In fact, Verizon's mouth probably has blisters on it from kissing Apple's butt so much lately.
And why would they do this? Simple. Their projected iPhone sales were well above actual numbers, and beyond the projections they were hoping to sell considerably more Apple devices than they actually sold. Their actual sales were such an iSlap in the face, that they continue to focus efforts (including emailing current eligible smartphone users to let them know that the MAGICAL IPHONE is now available to them!) on selling iPhones. I searched back five years in my email history (yes, I know, it's lame to keep emails that long) and I can't find an email from Verizon advertising another single phone model near to the extent they've advertised to me the iPhone. I received an email announcing the iPhone on January 12th, another on February 3rd, and another on February 8th.
The sales shortfall did not surprise me as much as it surprised them. They were
six months late in releasing it, and it only had minuscule improvements (other than Verizon's coverage map) over the AT&T&T version. So now they are kissing as much Apple butt as possible to make sure they get the next iPhone in a more competitive time frame, so that they are truly a legit contender against AT&T&T with the release of the newest, latest, greatest Apple device.
Need more evidence?
Sprint releases EVO.
AT&T&T releases Inspire.
Then, Verizon releases the Thunderbolt. Thought it has some spec improvements over the other two, they are the LAST major U.S. carrier to release a high powered EVO-ish HTC large screened device.
AT&T&T releases the Atrix.
Months later, Verizon will supposedly release the Bionic, with WORSE specs nearly across the board, other than the "truer" 4G antenna, which the majority of Verizon subscribers will still not yet be able to enjoy, and minus the speed of the RAM, which will be somewhat negated since the amount is halved.
What happened to Verizon's "everything iDon't, Droid does" mentality of yesteryear?
The iPhone. 
I can't seem to find a remedy and it kills me cuz i cant even make it through an entire day with a full charge
