I just judge it on income. I don't see any European pros getting rich on pool either. My view includes pool in Europe as well.
The sport is fragmented. Sure, in Asia, it is thriving more so than here or Europe, but the cost to compete professionally and travel the globe is more than what most earn in playing pool professionally. You know this, though, I'm sure.
Snooker, on the other hand ....
There are two things: 1) money in pool 2) reputation of pool. While money are not too good in Europe the reputation of pool is good,it is considered as a real sport in many countries across Europe even if a minor one. In that we are giving USA orange crush i guess..