The perception of Müller in this Forum really surprises me.
He is pretty emotional and argues quite a bit with referees and other players, but to me he always seems pretty open with these things and not in any way as cheap and dirty as we know it from many other players, more like a bit cheeky in his behaviour. (He only has 22 yellows, 1 yellow/red card in almost 400 club games and 3 yellows, 0 red cards in 76 games for the NT).
I have watched the majority of the games during his career and he never stood out to me as one of the "bad guys" (as in Pepe, Busquets, Pedro, Villa, Suarez caliber).