I suspect that the public vastly overestimates entertainment industry earnings due to availability bias. Headlines like "<Star Name> earns $XXM for <movie>" are more common than "relatively unknown supporting actor earns enough to maintain SAG membership."
Likewise, young women probably perceive the porn industry to be much more lucrative than it actually is. I've read that they get paid between $500 and $2K per scene. While that sounds amazing to an eighteen year-old working at McDonald's, it probably translates into $100K annually for three or four years until younger talent takes their places.
100k annually for three or four years is like 400k. That's ten years worth of a decent middle class salary, which is what most careers are worth, except it's front-loaded so you can generally invest it and make more in the long run. I would not snort at that kind of income.
Nor would I. But, a porn-filled past is stigmatizing. The same men who paid for a DVD of the young starlet would be unwilling to hire her out of college at age 26 as a marketing assistant. She's tainted, you know! So, it's a nice nest egg if well invested, but one must factor future opportunity loss into his NPV analysis.
I doubt they make more than 1/4 of what the younger stars make. Plus (so I've heard) they do some pretty gross stuff, hard on the body and psyche. I don't think it's a glamorous profession for anyone other than the top 1%. That may be true of most professions.