Is there a reason why communities are limited?

Is there are reason why only 45 communities? I'm thinking close to a few hundred at least. Plus, in follow up to my previous post. Can communities be hierarchical?

These are real estate communities I am thinking off. The parent community will be the larger, generic location. And the child communities more specific locations or properties even.

I was initially thinking buddypress groups but as pointed out before - would need a custom component that's hierarchical.

Any ideas are greatly appreciated.