Like you whenever I come across a gorgeous girl doing nude modeling or porn I'd think to myself, "I bet she won't have any problem finding work in the modeling business." or "I don't know why she would let herself get fucked in front of camera. Her parents must be mortified that their beautiful daughter is swallowing cum in front of millions." I always equate looks with education or background, so an above average looking girl should come from well-to-do families and probably have guys lining up to date her. Not sure why a girl like that would take her clothes off and letting a stranger (in some cases ugly strangers) just sticking his dick inside her. To me that makes little sense.
It might have a bit to do with your taste (not that you have bad taste, but a girl has to be liked by the general public and your taste
might differ a bit) , the fact that you don't notice small, but vital flaws, etc.
Besides, the looks - education/wealth equation isn't really correct. It's true that girls that are wealthy can spend more money on cosmetics and at a beauty salon, but even money can't change their genes (which is what makes the girls beautiful or ugly or... whatever you think when you see a girl).
So poorer girls can be pretty/beautiful as well.
I don't know for sure, but I believe a lot of adult entertainers from central europe do it to pay for their college education (If you read some biographies you'll see that's a very common theme. I'm not sure because I haven't read every single biography of every single adult entertainer...), so I doubt they're very rich.