Young people don't pay for porn so most members of pay sites are older and hate tats. It is true that girls would sell more without them. In my opinion if a girl has shitty tats she looks like a trailer whore. If she has nice work it can be real sexy buts let face it, some of these girls let their neighbor ruin them and get really cheap places to tat them. I have seen some really really bad ones.
Here is a pic of my only tat for people that appreciate them. It took 30 hours so far.