You're taking a bad-faith reading of OP's comments: they're not talking about the self-identified incels; they're talking about the majority of single men who are single involuntarily. The latter is the group of which the former are a part. They're not the same thing, and conflating them is disingenuous.

OP raises a valid point about the increasing numbers of single men and the possible long-term health and societal effects of having (say) 20% of men single for their entire 20s. A certain toxic percentage will become incels -- and probably always would have become something like that -- but the remaining 95% are a largely new phenomenon and one I don't think is being taken seriously. We're into new territory here and we'll only find out the results in 10 or 20 years time.

FWIW: I'm not an incel. I've been happily married for five years.