Personally I got it on release day, had preordered it. I never regretted this one bit, despite the bugs, the game was amazing, way better than anything else especially at this time and it was fine to me beta testing it and reporting problems while enjoying it so much and the bugs I was sure would be fixed soon.
But the problem is that for at least the way I play the game, it actually started getting worse from there. In the first major patch, we got that insane race director, hanging insane (5, 10 and more second) penalties for going slightly off track and even losing time, we had to spend so much energy in the forum, just to persuade the devs to tone it down a bit (it's still a big mess, but not as bad now). Later we got more problems, UI related, then the big multiplayer problems started, the huge disconnections, because in their attempt to fix the LiveTrack issues online, they made the game transmit a lot more data, and (still) now we have all those stability problems. Then another patch made a lot of the cars (like the GT3s) in this game almost undriveable, if you did not have a high end CPU in PC (I had a 4660) and were not using -pthreads 4 in the command line. Again, lots of energy spent in the forum to convince them that this is a real problem, while also having other people trolling around its our imagination etc etc. Eventually it was fixed in the next patch, some months later again...And so many other issues (old or new ones) that were not fixed at all at the end...
And in my opinion it is not nice that we did never hear an official announcement that the game is done, only mods in the official form told us about it and in the beginning at least we were not sure if we should believe it or not. The very few comments we were lately seeing from devs, were in threads where we were complaining about issues, and their comments were along the lines of "I was quite amused reading this" etc. In that context, I hope you understand that when anybody from the dev team suddenly does post, only to demonstarte how great PCARS2 is (which in a very large part it really is), it is logical that it is not taken too well by some. Please take this as constructive criticism, at least this is what it was meant to be.