[pdonis]

*> business ownership, which is much more rare.

First, you're assuming that all these "professionals" are not also business owners, which is often false; doctors and lawyers earning enough to put them in the top 1% are most likely owners of or partners in a private practice.

Second, if we restrict "business ownership" to those who are not "professionals", the fact that it is rare is a consequence of regulation, not an independent fact. Regulatory barriers don't just benefit "professionals" who have the requisite qualifications; they also hamstring people trying to start businesses not in those particular "professional" sectors.

So the result is only "not surprising" if you take the level of regulation we have now for granted.