There are two things to understand -- and the first is the most important.
1. No-one makes you upgrade.
When 2.1.x came out, everyone leapt like lemmings off the proverbial ledge to upgrade, not even understanding that it was not anything that they had to do. There was not, and still isnt, anything wrong with 2.0.11. If you were to hop in a time machine, the posts here were covered here in "the opposite of accolades" (I wont use the word complaints).
The same holds true, so far, for this release. You DONT have to upgrade. It's your site, not Matt's.
2. To suggest, as quite a few have, that expressing an opinion that doesnt contain a "yay!!" is complaining, or too much complaining, or whining (taken from another thread) is ridiculous and out of line.
Obviously, there is plenty of gratitude, and "love" for WP or ppl wouldnt take the time time and effort to upgrade, fix the problems, post here, etc.. They would ditch it, and go install something with a smaller footprint.
In fact, just because something is free, doesnt mean that you absolutely adore it, or have to. This is a support forum, not a hugfest, and consequently, the posts here are largely going to fall on the side of those that are having problems.
Problems make ppl unhappy. Unhappy ppl dont say nice things.
Appreciation does not have to be blind. Were it, it wouldnt be real.