I think the best challengers should get a little bit more points, the worst ones should get a little bit less. I think there's not enough difference, people always speak on this forum of "challengers" in general but there's a very big difference between the best ones and the worst ones, and I think the ranking system doesn't mirror enough that difference.
The only objective way to do it is based on prize money, you can't say "more for European challengers, less for Asian or SouthAmerican ones".
The problem is that often, big challengers are located in Asia where the list are usually weaker than in Europe or America.
I wouldn't say that "the big challengers are in Asia" : the challengers in Asia overall give more prize money than their level would suggest (but they cost more for most players, and well that's a good compensation) then they also give a little bit more points than their level, considering that the objectivity of the system makes a connection between prize money and points,
but among the challengers which give most prize money, there are more European ones.