Maybe unfair is not the right word.
I think there are limitations already in place, the ones I mentioned in my other comments. So managers already have to be a bit careful how many changes they make.
It's annoying as heck watching the manager march out there time after time, no question. But it's part of how the game is played now. I don't think we should be making any intrinsic changes to the rules here. There are other 'bigger fish to fry', perhaps.