At the end of the day android is not a true operating system, it is marketing device from Google (a website, not a hardware manufacturer) which works fine on phones and low specification handheld devices. You do not see desktop makers rushing out "android" pcs do you? A great shame, a missed opportunity.
So Android isn't "the collection of software that directs a computer's operations, controlling and scheduling the execution of other programs, and managing storage, input/output, and communication resources."? How exactly does Android fail this is any way (yes, the smart phone IS in fact a computer [a general purpose device that carries out a finite set of arthimatic and logical operations]). What I think you mean to say is that Android doesn't scale across the entire class of computers from small portable/embedded systems to home PC's. This is quite true, and could be said about any OS (with the exception of a few strains of linux that aren't easy to deploy).
And of course Android isn't made by a hardware company. Because it's SOFTWARE. Microsoft isn't a hardware company either (ignore their myriad failed attempts at it). Apple is, but they really are exceptions to the rule. Oh, and FYI unless I'm mistaken iOS doesn't have printer drivers either (but they have similar remote/cloud printing services).
Now as far as why there aren't printer drivers for Android. There are many reasons. 1) very few android devices can host USB devices. If you can't host the device, the having a driver available won't do you any good.
2) with the various remote/cloud printing services, you don't need drivers in a number of situations
3) printing is most important when you are creating content (writing papers and whatnot). Since very few mobile devices are used that way, there is less need for printers.
4) the printer manufacturers would have next to no incentive to develop android drivers, since the population of people wanting to print from a specific phone to a specific printer will be miniscule. Even if 20% of the android owning population wanted to print from their phone, how many of them will be using the Droid Razr with the stock .212 update, printing from a Lexmark e342z8 ink jet All-in-one?
remember that the printer companies develop drivers, not the computer/software companies. They certainly collabarate, but the buck stops with them. Developing printer drivers for a specific printer will be quite costly, will only help a handful of people, and will not increase sales. In short there is no reason for lexmark, epson, cannon, etc to invest money into Android drivers.
Oh, and it's bad form to dredge up threads that have been dormant of almost a year.