I will say that among my favorite moments on TNG were episodes where Patrick Stewart, a very fine actor indeed, got to play Jean Luc Picard, Lousy Actor, whether in the holodeck or on stage in one of Bev Crusher’s community theater productions. You have to give the guy massive credit for managing to be so convincingly, effortlessly cringe-inducing in his affected badness.
It’s funny, though, we almost always saw holodeck episodes, at least the earlier ones, as things where the bridge crew in general were sort of awkward and self-conscious about what they were doing, which seems sort of weird if taken at face value: this holodeck thing is the best video game ever but everybody’s all weirdly stilted about it? But it’s not so weird if you accept that it’s these characters, specifically, who were bad at it. Maybe because they were career-minded enough that they just didn’t get time in there? Maybe because they just weren’t naturally disposed to that kind of thing? Or maybe they were just a bunch of squares, I dunno.
Reg Barclay certainly knew how to get into the spirit of things, at least until everybody went and messed that up for him, so clearly the whole awkward inhibition thing wasn’t a constant.