Because I was so appalled, I asked one of the students to explain it. They said that I was disabled because I can't work in a noisy factory comfortably while they could.

I applaud that part; seeing the upside is admirable and not everyone can do that. What I still don't get is when they get mad when others try to hear again. It just doesn't make sense. My perspective could certainly be off here, but it sounds like someone being mad his neighbor has a fancier car and yelling at him about it.

The problem is that you get hearing people go "well, there's a treatment, why should we change what we're doing to accept deaf people?"

When there's a (potentially invasive/experience-altering) treatment which makes people more able to fit into existing society, that society will often pressure people into receiving that treatment. This is, obviously, rather upsetting, and I imagine a lot of deaf people would rather the treatment didn't exist.

Your perspective suggests you think deaf people are jealous of hearing people. I think it's different. Deaf people have created a bunch of other solutions that don't involve cochlear implants, and a lot of that has been ignored by society at large. (For example, how do you raise a deaf child.)

Also the controversy around cochlear implants is mostly about giving CIs to young humans. It's not that much about "hearing again". (In fact I don't think CIs are as effective later in life.)

And were you able to see one of the other meanings behind "disability", and why deaf people want to avoid that stigma?

I could see their perspective, yes. They also mentioned that they could communicate at a noisy club easily while I couldn't, but that doesn't have much to do with being hearing/deaf but exclusively due to knowing sign language. My conclusion is that they actually are disabled, but no less deserving of respect and love as those who can hear.