...Man, I'd kill for 60 FPS in DOTA... But a buggy internet connection leaves me at 100 ping at best, 450 ping at worst. No packet loss, just sloooooooow and really jerky at times. Playing initiator/support sucks just as much as carry if your internet is blown, ladies and gentlemen.
But for Minecraft and more slow-paced games, 30 is just what the doctor ordered. As someone said above, getting deep into a game makes people forget about constant framerates if they're above about 25.
Also, just as an aside, to anybody who "can't stand less than 60 FPS"... how do you watch TV? Or stand a movie at a cinema? I thought most, if not all, broadcast media was released in 24p nowadays, and that a higher framerate is indicative of lower quality work, as that's the demesne of home camcorders.