Incel is a hard word.

Because it was originally a slur

but, to a certain group, it described their poor situation.
And to them, it has much more meaning.

Something like: i haven't had a girlfriend, i will never have a girlfriend, girls don't even like to talk to me, they get this disgusted look on their face whenever i try, and i would really like a girl to love me for who i am.

So, the words involuntarily celibate is really a misnomer... but how do you pack all that into a easy to say package?

and BTW, the entire "incel" mindset keeps one being an incel, so there is no way out.
Also, the way out is very difficult and most who have made the journey have said it wasn't worth it for today's women.