Yeah it's a tough one, designing a project for load you may never get is a real waste of development time, so for most people they wouldn't have had to deal with anything at large scale.

It's the same in any field really though, even supermarkets are reluctant to hire people without relevant experience that you can only obtain from working at a supermarket.

Guess it's all about getting a lucky break, impressing someone enough to give you a chance, or getting lucky with your own venture that it eventually gets up to a scale where the same concepts apply.