I think one reason you don't see a lot of older folks applying to YC is not necessarily for this reason. The most talented older people, the ones who would be getting into YC anyway, presumably have been in the industry for 20 years. When you've been around that long, you tend to already have plenty of connections. You're already tapped into the silicon valley network. So why bother going the route of YC if you can already secure meetings with investors without them?