Just to be clear, this is a pirate site, right?

It is very much a pirate site. I've used it for old stuff or for looking up stuff I own. Aaand... for stuff I've been interested in. If I've fallen for a game there I usually buy a copy.

Yeah, if you find stuff you like and don't buy it, you're shooting yourself in the foot, because then the authors don't get paid and will starve and won't write more stuff you like. Supporting writers (and artists and musicians) that you like isn't just the right thing to do, it's the smart thing to do.

Assuming these are books that are out of print, they wouldn't be losing the copyright holder money, generally not making it worth litigating. Plus if it's out of print and not likely to ever come back into print the argument can be made for archiving them before they're lost to history. In fact, taking pirates to court to prevent historical archiving when it seems any reprinting is unlikely could result in having the copyright revoked, as I understand it.

A lot of this stuff is not out of print.

(edit) I'm being a bit pissy about this because I saw on their front page they have Lancer, which is an indy RPG released just last year, still being sold for about $25, and which was written by an artist I like rather a lot. I'm not particularly concerned about piracy of A) old stuff, or B) stuff from major publishers that aren't hurting for money, but this is basically brand new indy publisher content and that, sir, is not cricket.

They had Tasha's before it was even released for sale