Haha, while sexual attraction is based off of looks, sexual PERFORMANCE is an entirely different story.
Sexual performance is like a play, except instead of a stage it's played on the skin, and instead of an audience to please you have nerves to entice.
Knowing exactly what to do and where, perfectly timed and expertly executed is a lot different from having an amateaur just fiddling around, not sure of anything.
This is why married women tend to be sought after by a previously married man, because he wants someone who already knows what to do. I guess that also explains that whole MILF fetish...

I dated this older guy once when I was like 15, he was 38. I mean, he was really sweet and amazingly kind and charitable and even to this day he's become my best friend despite the closure of the relationship he and I once had. I didn't find him attractive one bit though, even though he was an expert on how to hit the nerves.
So, sexual attraction does play a part too, if your body simply isn't turned on then there's nothing to work with.
But once it is... hahaha.