You don't own a game. You own a license to use the game. You don't own the code or the images or the files. End of story. You don't get to use those files and images to make something else and sell it. The mod wouldn't work without the game - there'd be nothing to display in VR. When you mod you are directly using the work produced by others and adding in top of that. Modding exists because companies allow it. Part of that allowance is not being a dick, which this modder 100% was. They didn't even tell him to take it down, just make donations optional and he threw a hissy fit an refused.
Yeah, there's plenty of nuance. Nuance showing that the modder is a jackass. Should I remind you this modder did THE EXACT SAME thing with Rockstar as well already.
This guy is just a tool trying to make as much money as he can before moving to another game and doing the same, rinse and repeat. He's a scammer and a grifter.
Fuck him.