I agree that entrepreneurs tend to be a bit self- (or at least startup-) absorbed, but I'd bet most normal people don't mind being called "normal".
In any case, the dichotomy is real, though the "non-normal" side is not restricted to startup founders. I've heard the term "real person" used as a near-synonym for "normal"; a "real person" has a job, probably has a mortgage, and is either married with children or well on the way. In other words, a "real person" is conventional. Unconventional people tend to think of "conventional" as an insult, but it's simply not the case; by definition, most people are conventional, and most of them are perfectly happy that way.
In any case, the dichotomy is real, though the "non-normal" side is not restricted to startup founders. I've heard the term "real person" used as a near-synonym for "normal"; a "real person" has a job, probably has a mortgage, and is either married with children or well on the way. In other words, a "real person" is conventional. Unconventional people tend to think of "conventional" as an insult, but it's simply not the case; by definition, most people are conventional, and most of them are perfectly happy that way.