I don't think you understand incels at all.
Yes, some are emotionally and/or physically violent. This is not a new concept and these kinds of antisocial men have existed long before "Incel" became a term.
And yes, some are perfectly normal and dateable men who have had a string of bad luck.
Most are part of neither of these categories.
I mean, the way you are talking about them is "Incel" = entitled, misogynistic, angry, bullying, anti-social, violent, and objectifying.
You qualify it with phrases such as "many" or "for the most part," and then give extreme examples to claim your adjectives as applying to the entire group. I think this is getting dangerously close to typecasting a huge swath of men into this reputation that is untrue and impossible to get out of - very similar to how blacks were characterized.
Involuntarily celibate men are still humans. Very often disempowered humans. Depressed, suicidal, traumatized. They deserve empathy every bit as much as trans people, or detrans people, or women, or any other group.
I will agree with you that you have no obligation to provide care, love, and sex. I agree that men who believe they are owed these things need to get a grip. And nobody is entitled to sex love or attention - although love and attention are legitimate emotional needs, that too often these days go unfulfilled.
But many of your points, and also many "anti-incel" people, choose to be more judgemental than compassionately understanding, and this drives the conversation away from any possibility of a more "socially connected, empathetic culture." And that's not helping.
You don't have to shoulder the burden yourself. Men do have a lot of work to do on themselves. But it's not as simple as "reasonable-looking men who could have put in the work to improve their social skills...instead they choose to hate, dehumanize and sometimes kill women as scapegoats." Young men these days have precious few leaders showing them how to improve themselves. And that I think is what's needed most.