Incels are a cult of hateful, misogynistic extremists who consider mass murderers like Eliot Rodger to be heroes. Simply not having as much sex as one would prefer, or any at all, does not make one an incel.
It literally does though. You can't change definitions because someone gave the name a bad rep.
If you want to take 'incel' back and try to reclaim its neutrality and separate it from the toxicity of the culture, you'll have as much luck as someone trying to claim the alt-right movement isn't really about racism, even though racists have been all over it since the beginning.
Yeah, but that's really like saying "but people can be happy while they are fasting" to somebody that is being starved.
Something being voluntary often makes the difference between it being considered harmful or even torture and a weird thing.
In aggregate, less sex may be a bad thing. In aggregate, more sex may be a good thing. That's what's being discussed.
Individuals and anecdotes just distract from the discussion.
Dating any of these would be profoundly bad idea. It is better for a woman to be alone then to be with someone who has opinions of incel.
If not, go visit a forum for incels and see how happy they are.