I think a lot of people who paid for it (myself included) did so because surprisingly many people in sim forums said it's actually decent. What I think is really happening, is that a lot of those people who bought it early are actually in buyers remorse and trying to convince themself, and others that this thing actually has some promise of delivering a good sim. The exact same thing was happening with the whole War Z scandal, yet there's still people out there who lost their money claiming it's all great, money well spent, nothing wrong at all, everything will be fixed in the future.
In hindsight, I wish I had followed common sense and not paid any attention to PCARS, since Slightly Mad have zero track record as of yet at delivering anything realistic at all. Sure all devs have to start from somewhere, but when you base your racing simulator on the NFS Shift engine without scrapping the physics code, you're going ass backwards in to a cactus. It pains me so much to see ISR advertise PCARS to be "right up there" with actual proper sims, making more people buy in to it.
If anyone is tempted in paying for PCARS because someone somewhere has said it's cooking up to be a great simulator, all I can say is don't do it, if you want something even remotely sim-like. It might turn out to be some kind of a Forza competitor for the PC, but this is not the sim you're looking for.