Sorry, couldn't help, but,
Dysfunction might be the right term. If their system was functioning, then they'd be sexually interested and active (though obviously everyone varies in how much). Then again this sounds like it could be used as a sort of judgement.
Sure sounds like a judgment to me. Establishing norms seems fine, but calling what is outside of them, whether we're talking about behavioral or physical traits, seems to me taking a wrongly judgmental standpoint (given an evolution view of things). I would call them variations, possibly beneficial variations. I think bees might be a good example of a place where asexuality works out.
Not that I'm trying to scold you; I do note you expressed uncertainty. Just to take time to express myself on what I think the right vocabulary and thinking on the subject is.
The only truly dysfunctional people to me, in a sort of judgemental way, are those that have a functioning sexuality and then want to pretend they don't and that that is the inherent state of humans.
It's a tough call. To what degree do we think of ourselves as animals, and whatever we do is "OK", and to what degree do we have some "ideals" that we're forcing upon ourselves? And to what degree are those "ideals" implementable and sustainable?
Trying to "gain an upper hand" on sexuality isn't obviously bad to me. I see some utility in having control over any urge--it allows people to make decisions by weighting values as they (mentally) wish. Then again, I also am unsure about it. With no intrinsic values to things, we become less human and more decision-making machines.
Lots of words to say, I can't agree or disagree. I haven't decided yet.
Ben