No you misunderstood. If you have used android applications on devices with different screen resolutions (eg 800x600) you soon come into contact with many problems (I can vouch for this because I purchased the Herotab for $150 on ebay). The elements become stretched and shrunk and some are shifted out of the screen, and some applications refuse to start. Hell, you can notice some of this on the MotoDroid because of 3.7" 854x480.

What I'm trying to say is that Google should've pushed hard with making apps fragmenting the user elements for the specific pixel density and screen size ... but Google could've used a little foresight and choose the 800x450 or 800x400 resolution on the Nexus One. Yes losing 30-80 pixels isn't a great thing but the screen density really doesn't suffer too much and it makes it a real treat to use the tablet when it allows the user to use it in such great form.

And this strategy would push developers to make applications for the smartphone, then also give them time, to port their application to the tablet's native resolution (1600x900 or 1920x1080).

Think about it, as a developer you have your ideas for your application, and if you follow a simple resolution "rule of thumb" 800x450->1600x900 or qHD->FullHD, it makes it that much easier to reach out to more devices (as you require less testing) and potentially the time you saved can be used to make the app more polished (which is what I'm constantly hearing from iOS developers that made the switch to android).

Here:
800x400 on 4.5" is 199PPI
800x450 on 4.5" is 204PPI
800x480 on 4.5" is 207PPI
854x480 on 4.5" is 218PPI
960x540 on 4.5" is 245PPI
(it only costs 3-8PPI which isn't that much, do note that opthamologists say any amount above 220ppi cannot be detected by the human eye at 20cm from face unless stared at for over 60seconds on non-moving objects which really never happens, but the quality of screen used can definitely be picked up with the first glance sometimes even with moving objects)

edit: I failed to explain myself again.
I'm saying android is pretty good the way it is right now, but its not perfect and this is because developers are lazy. If Google chose the same path but pressured other OEMs to stick with 800x400 or 800x450 then most (lazy) developers would make their app suited for 800x400/450 and this would scale perfectly for tablets. If developers weren't this lazy there would be no need for this but that isn't the world we live in, which is why such a strategy would've been awesome is all im trying to say.