I think the 'scalable technical structure' is key here; up until some years ago, if your application was growing, you'd need to rent and manage your own servers. Nowadays one dude can just upload his application to Amazon and have it scale automatically with no real hassle. If this was ten years ago, the first hired employee would be a sysadmin.

Nowadays though, as long as you have a good idea and some reasonably basic skills, you can make an app for millions of people.