I don't think it is just a question of attraction. I think it is a question of what is right. The transition between being in high school and living at home - and living as an adult and away from home - I would think is enormous. To plunk someone - male or female - out of that and bring them forward past half a decade - in my opinion is wrong. Its not that the 15 or 16 year old won't enjoy being "an adult," but that person could never recapture what they lost.
Although it never applied to me, I would think that the ages between 15 and 19 would incredibly unique and formative years that could never be returned to if bypassed. There is no way to know what that person would have become or what doors would have opened or insights learned. Seducing high school kids with adult ways is wrong in my opinion. Leave the teenagers alone to be teenagers.
I had very little ethics or values in romance. No woman nor anyone else every would say I as a nice guy. It wasn't about niceness to me. Certainly no interest in relationship and whatever I got into with a woman I was singularly in it for me. Whether she enjoyed it or not was her thing, not my concern. My only concerns were was I interested and if so did she consent. It began and ended there. But I'd never touch a teenager. There was too much potential damage to be done in my view of it, nor did I want children anyway, which is how I saw them. They may be experienced and so-called street wise, but didn't have a clue really what it meant to come into my world and ways.
What's so hard with the concept of adults should leave the kids alone? 1 year, 2 year difference? OK. Otherwise no. I'm certain other people's wives/husbands can be highly attractive and may even make herself available. Leave them alone too. In my not-humble opinion, adults shouldn't **** kids and other people's spouses. If you can't find someone else among the BILLIONS on this planet I think you got a real problem.
The ONLY exception I MIGHT see is if the goal is marriage, not sex. Sex is cheap, easy, trivial if just for sex. Seeking a spouse? That's real. I could see a 20 something not passing up someone he/she sees as "THE ONE."