When I was younger I could probably handle a weirdo office like this for a year or two. Now? No way. I need some level of quiet, non-social time, etc to be focused and get things done. I imagine environments like this are the equivalent of saying, "We don't hire anyone over 30."
Moreover, "We don't hire anyone over 30" means "We don't hire anyone good".
That's not to say there aren't good people in their 20s. There are quite a few of them. But they want to learn from people who are better than they are. That's the trait of A players: they want to learn from the A+ players. If you don't have anyone over 30, then the good under-30 people you get will quickly leave.
