Uncomfy to me - when I think to use it - means "I feel like this is setting up something that will squick me", but it has a connotation of wrong, as though things *should* be comfy.

I've... never thought about it in this way before but... yes, this. Absolutely this. There's an inherent value judgement there; not just that things "should" be "comfy", but they should be so according to the whims of the "uncomfy" person.

It's that whole "you have to curate my enjoyment" thing, wrapped up in cutesy language.