These sites seem to be run by idealistic individuals, rather than as a profit making enterprise.
You really think people advertising adaware 'Improve PC performance now' and 'watch XXX live with donkeys' are idealistic individuals fighting draconian copyright laws?
Also I don't know about kickass - but for example the /scrape endpoint is blocked on the piratebay tracker (and most other 'commercial' trackers) -- meaning that you can't get basic statistics (like leechers/seeders) about a torrent which is tracked by them without going through their advertisements.
By the way, TPB hasn't had a tracker for seven years now.
That seems like a pretty fallacious leap to me. It may have a lot of users, but all those users add expense, and most of them are savvy enough to use an ad-blocker.
Quite frankly, thousands of users does not a millionaire make. I'm sure we'll see more details in the upcoming suit though.
You're seriously underestimating KATs size.
There's no chance they weren't making millions off of the site (and various other similar sites they operate).