A critique of Piatek's shitty attitude is less about love of Milan, and more about a warped sense of self.
Sure. Maybe players look at Milan as a way station. Paqueta, Theo, Bennacer, Leao, etc.
The difference is that unlike Piatek, other players have sought to improve, and play with hunger. Theo does. Bennacer does. Paqueta tries hard but he looks lost, he looks like he's overthinking and trying to remember what he's supposed to do while being placed in an unnatural position nearly every game he's played this season.
Piatek plays like a primadonna. Like he's Lewa scoring 40 goals. He's got the touch of a donkey, doesn't work hard, and isn't putting away chances. Against SPAL, he missed two chances a striker of his supposed class should put away with his eyes closed.
Piatek has a shitty attitude, he falls over whenever he's touched, and acts like he's MVB. He's not. He's not talented enough for that. If he learned from Pippo, he'd be able to continue to score, he always makes the worst runs and can't finish with his suddenly dainty approach to matches.