In article ,
Alpha Propellerhead wrote:

All commercial pilots started
as private pilots, and private pilots are a revenue source for
instructors, the FAA, mechanics, manufacturers and the rest of the
industry... Oshkosh being the best evidence.

Mostly, even overwehlmingly, but not invariably.

In an earlier incarnation, I worked for IASCO at Napa, CA.

Their main business at the time was ab initio training of JAL pilots. From "what
is an airplane?" to Falcon 20 certification (plus B-727 flight engineer) in one
long slog. The students may have technically been private pilots at one point,
but for all practical purposes they were students from day one through
graduation (at which point they went back to Japan to work as baggage handlers
to ticket agents, etc. until sent back to the U.S. for the flight engineer
training).