1) Lukaku definitely needs to improve in some aspects, especially when, as some of you say, is up against tough and physical defenders. I remember a couple of games where Koulibaly and De Ligt - just to name some - have had him in their respective pockets.
However...
2) When a referee is so incredulously hell-bent on ruining a football match in favor of one team as the match this latest discussion takes hold in, there's nothing anyone can do about it, let alone Lukaku.
Chiellini - as is always the case with the single most protected player in Italy - did everything he wanted to Rom with no repercussions, and if Lukaku even tried to do anything remotely physical in return, the whistle was going in one way, and one way only. At that point there's nothing you can do - not with the way our game is setup, with Lukaku receiving the ball with his back to the defender. If the defender can do anything he wants to against you, and you have no chance of returning that physicality without being punished with a foul for it, it's time to pack your bags and go home.
Remember, this is a football match where Chiellini held onto Lukaku, fell backwards on his ass, kicked the ball directly into the net and Calvarese was there - like clockwork - to bail him out at first.
You also had Lukaku fairly going for a header, touching Chiellini at the shoulders with his shoulders, Chiellini flailing and screaming, and Calvarese ruling out a potential goal of the season without as much as a second-thought. Immediately, blink of an eye stuff.
I agree that Lukaku can do better on a general level when it comes to not being outmuscled or outmatched physically, but against Juventus? No way man, not when the odds are so clearly stacked against you. The scum referee had decided what way he was going to whistle before he even stepped onto the field.