That seems like a pretty reasonable assessment. I don't think most people would have as much of a problem with him in this role if he'd been able to depict the "heavier" (relatively speaking) scenes better. I do think that LGBTQIA+ roles should be reserved for LGBTQIA+ people, but it's not like this movie was completely devoid of gay actors--Andrew Rennells did a great job and got some solid screen time.

I'm not completely sure if the issue is that he's not a good actor or if he lacks the life experience to portray a character who experienced being kicked out as a child. If my memory of his short time on Doctor Who is any indication, I'm leaning toward him just not being a good actor, to be honest. Another cishet actor could probably have played this role better.

So, it may be a healthy dose of both. His sexual orientation seems to have impacted his acting ability in the role, which made the depiction come off as mildly offensive and stereotypical, and a queer actor could have most definitely connected better to the character and done camp without it feeling so shallow and cliche