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.
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.