"Can" is different from "will". People place the blame at Lue's feet because this team doesn't run a motion offense or sets the way some other teams do.
But the fact that people seem to ignore is, we have run those things at times, and those things are called at other times and abandoned or ignored. The reality is, and the fact is, that Lebron feels we will be more successful if he just "creates" offense on the fly using his skills. And with a player like Lebron, no head coach in the league is going to change his mindset. The only thing that would change this reality is if Lebron has talent on the floor that he feels is comparable to his talent and BBIQ. And that doesn't exist on this roster.
To be fair Lebron is just trying to give himself what he feels is the best chance to win. With the vast majority (if not all) of other head coaches and rosters, Lebron is going to believe that he himself "creating" the offense on the fly will be better than him being a cog in a Brad Stevens type system. People thinking Lebron would just blend into such a system is a pipe dream, while he is playing at his current level. When he starts to decline, perhaps that will change. But no way in hell it happens now.
If he were to go to Philly there would be no real system, but Lebron would "take turns" creating offense with Simmons, the same way he "took turns" with Kyrie when he was here. No system, just set the floor and let the play makers create.