You must consider too that many entrepreneurs start several businesses through out the course of their lives. For each attempt, an entrepreneur would increase his/her chances at attaining wealth by 5%, no?
Agreed, I don't think you'll ever succeed in your business attempts if you're not providing something new, original or just not established in the area. You'll make a killing opening a coffee shop in a moderate sized town - as long as there's not 3 Starbucks already there.
There's a lot to business beyond the idea, hence it's important to be a businessman once you've succeeded your entrepreneurial dream of getting a company started. You don't want your company to fail just because you fucked up and didn't file your taxes.
http://www.wolframalpha.com/input/?i=0.5+%3D+1+-+%28.95+^+n%...
That's not to say that multiple attempts at starting profitable businesses won't teach you things, and increase your chances of success, your chances of picking the right strategy out of the gate, etc - but there is no simple "Hey if you list yourself as "entrepreneur" and keep trying, you'll end up rich.". Many people just end up wildly in debt and failure.