I think the context is important. If he'd moved from QPR to Rangers normally, fine, they're offering more money and we'd all move jobs for a significant pay rise.
The thing that annoyed QPR fans was him going for and then turning down the Wolves job, professing loyalty, and then going to Rangers. Wolves are surely offering more money than Rangers and the PL is a much much bigger deal than the SPL, even if you're a non-European team. Hence many SPL players or managers making the move to non-European PL clubs. No player is going to pick Rangers over Everton because they get to play in the CL qualifying rounds.
So the fairer comparison is Wolves to Rangers, not QPR.