Or people could try to share power with fellow players, particularly newer ones, instead of playing margrave/duke/kings.
Who is to say that he isn't? Or that any of the dozens of people in this scenario aren't? Rulers know as well as anyone else that you need to keep the carrots in front of the players. That doesn't mean this isn't a problem.
The game permits rulers to hold land but it does so through a very roundabout means. Even that is preferable to the previous system of 'rulers can't hold land except in tyrannies.'
The way BM handles this is very clunky and gamey. If you don't want to allow it, don't allow it. If you want to allow it, make it do-able in a way that is intuitive and makes sense.
