There’s nothing wrong with feeling that way. Solo travel is not for everyone, but I do think everyone should try it once to see how they feel about it. You have tried it and it isn’t for you. I think whether someone is an introvert or extrovert plays into it as well. I do take a couple non-Disney trips per year with friends or family that I enjoy and look forward to, so I understand how having traveling companions can make a trip fun. I just don’t necessarily need that dynamic at Disney to have fun.
I am currently living solo and when working in the office, two of my four workdays are solo there as well. I have even traveled to the UK solo, which I probably wouldn’t have done if I hadn’t been comfortable going to Disney solo. I get a lot of vacation time, that is use it or lose it, and my friends and family don’t get nearly as much. I enjoy traveling too much to miss out just because I am on my own. But it is not for everyone, and that is OK.