Only a handful of games here (~30 out of ~3000) have a pay option (that I've seen) and there's no real issue with it, you're supporting ArmorGames and the developers, and it's entirely optional.
It may not be the completely free AG you remember, but as sites continue they'll most likely need more ways to support themselves.
It's not. AG has changed considerably in the last couple years, but it's not evolving into a pay per play site. Apparently, you're just spouting off steam because you failed to keep up with the site.