why are incels frowned/hated upon?

While the incel movement may have seemed to be just some men who found community in others who haven't been in a relationship, something rather innocuous. It very quickly got hijacked into what it is today. It went from "I haven't been with a woman yet but I'm still looking and in the mean time i have my friends" to "It's women's fault that I haven't been with one and they use sex for power and are horrible people" and it devolved into worse things from there. The incel community was preyed upon by misogynist far right fascist and nazis. They were assaulted with propaganda in their communities, a place they had finally found that they were comfortable in. And when you are around those you care about, and they start espousing bigoted beliefs, some start to agree with it, and then most of them fall for it. It's not unreasonable to want community. Everyone wants that. But the incel community quickly became a community of people who hated that they were virgins and were willing to take their anger out on others. Particularly women identifying individuals.

You say they are lacking in a way they can't get women, I don't think is wrong. They really haven't been taught well by our society how to interact with women. They're trying to get into a relationship using what they've been taught, but they're floundering, reasonably, because society has taught them to view women as sex objects. Incels as a movement are a failure of our society, a failure of us teaching our kids how to act around others, including the gender they're attracted to.

I'm not nearly read up enough to give you much more information, but if you want, there's a book called Escape from Incel Island by Margaret Killjoy. It's really good and helps explain things far more eloquently and fully than me, a random lemmy user can.

Also, never having been in a relationship doesn't make you an incel, it just makes you someone who hasn't experienced that yet. And that's okay, we all grow at different speeds, it's okay to not having been with someone. We attach way too much to the idea of being with your first person. It's important to be able to respect and care about yourself somewhat before getting in a relationship, and it's okay if that takes a while. I didn't have that experience until my mid 20s, but it didn't make me any less of a person. Just remember to respect yourself, and to respect the others around you. And also don't treat women like sex objects, we are just humans, like any other. And there are 100% multiple people out there who will be interested in you, even if it takes a while to find one. I know you'll find someone, especially considering you're asking this question. You're willing to ask about tough topics and that is something a lot of people can't do. So good on you.