Actually, I think this is less common now than it was 20 years ago.
There was also no global internet allowing for an instant global market to be serviced from the middle of nowhere. If you started a business in podunk, your market was the podunk area. (For the most part, there was mail order and stuff, but that still had a higher barrier to entry than the internet does now.)
So I think things have gotten easier and a lot more people are doing it.
I'm interested in hearing why you think the opposite-- I bet you're observing a different trend than I am focusing on. (eg both trends can be true)