A casino is free to ban whoever they want for whatever reason they want. I wouldn’t hold it against them if they decided that a single player was getting them bad in the pocketbook and decided as a result to no longer let them play. Whether it’s the result of their play style or a lucky streak, every run has to come to an end for some reason.
They have the very right to ban players if they find their activities suspicious. It can be suspicious if the player has been winning consistently for some reason. They can create their own ground for doing it which we can't do anything about. The only down side of this is that it could affect their reputation negatively especially if the players they were banning will file a complaint against them if they aren't really violating their TOS.
There are lots of situations like this wherein winning consistently is what they set as grounds for banning which I think is unjustifiable especially if no rules has been violated.