And when (not if, as it's much more likely to fail than succeed) your flight school goes bankrupt for dozens of reasons it doesn't pay as much as being a CFI for a different solvent business.
The very last thing I'd do is start a school to provide basic flight instruction. I didn't even do that back when I actively instructed since the demand just isn't there in most municipalities. Getting into more specialized instruction can be somewhat more lucrative and establishing your own network of good clients (think Wolfala) is extremely beneficial but it's not going to make you a fortune. It's poor advice and I think you'll find those who have done it (and I'm not suggesting I'm the beacon of experience in the matter) would agree.
Whether your school succeeds or not depends on you. Most people suck as business management, it does not mean that those that are good should look at the statistics and not do it.
I never said anything about a school that will provide basic flight instruction, I just said flight school in general.
Here is a perfect example of a small good flight school, Tutima Academy, people go there from all over the country. Sean Tucker doesn't just know how to fly good he also made good business decisions. I don't know how much the guy makes, but I bet it's a lot.