To me it also reeks of feigning difficulty. I'll see someone playing something akin to Fur Elise and moving their head around like they're making such an effort. For some reason when I see a violinist doing it, I like it. Maybe because I don't play violin. But when I see a pianist swooning around I just ROLL MY EYES.
Personally I like players that look really intense like they're playing a video game. Like they're trying to get it right. Like a boxer who is focused and maneuvers around with dexterity I envy.
People that are overly emotional seem like they're playing to the crowd.
And I agree, I have some emotion when I start learning a piece. I love how it's new and how it sounds. But on round 100 I want to vomit on the keyboard. It's no longer new, it's tedium.