Jay Honeck writes:

I always figure it's an IQ test.

I doubt it. It's a matter of personal preference, and (in some cases)
professional obligation.

Human beings, for the most part, seem to enjoy living together. Even when
there's plenty of space, they gather to form villages, towns, and cities.
There are some people who enjoy small towns and wide-open spaces, but most
people seem to like cities, either for their own sakes or because of
advantages of city life, such as centralization, variety, etc. Some people
are obligated to live in large cities to work; they usually are unhappy.

Paris is a beautiful city with a lot to offer, so it's a popular place to
live, and since the city itself is quite small, the price of housing is very
high (although London, Manhattan, and Tokyo are much worse).

From an aviation standpoint, Paris is not necessarily very attractive. There
are three major airports serving the city, but they are quite a distance
outside the city limits, and they are limited mainly to commercial airline
traffic and cargo. The most active GA airport is apparently the tiny
Toussus-le-Noble airfield just south of Versailles, but it is not served by
public transportation and doesn't have much in the way of facilities compared
to many large GA airports in the U.S. France as a whole isn't very favorable
to GA; it was early to enter the aviation field but today many obstacles make
it extremely difficult to fly for fun in the country.