I can quite easily induce or control fry in my voice, so I assume that others can as well. Indeed, it's something one can be trained in or to avoid. It seems perfectly likely to me that for some people, at least, it is an affectation. Outside of disease or a few edge cases, I see no reason to treat it as beyond criticism.
, yes, if I think about it and make a conscious decision to do so. I don't
, and I don't think that most other people routinely do either. There are of course likely to be some exceptions, but I don't think people consciously decide to uptalk either. It's an affectation that is developed according to the culture a person is embedded in, like whether you say "haitch" or "aitch", not a deliberate choice.
That obviously doesn't mean that I think that it's beyond criticism. When I was podcasting, I made a conscious choice to avoid fry as much as I could because I knew some people had a negative reaction to it and that might have caused people to stop listening to my show. That is, in my opinion, one good reason to avoid it.
But I don't think most people think about their voices that much. They just speak and aren't concerned about how their voice sounds to others. Again, there will be exceptions.