Let me offer some real examples.
Let's say I am a part of not as much a clique but a circle of old like-minded characters. Let's say a new noble appears in the realm and somehow manages to get an important title. Eventually we realize he is not ideologically close to us at all. In fact he is our opponent and might potentially be a problem for our reign. As a player I would absolutely hate it we could just throw him out of every position by spam-protests. We'll completely own the realm fair and square... and where's the fun in that?
Another example: Let's say I was recently appointed a Duke and I've noticed many nobles in my Duchy are not participating in wars, refuse to do courtier work and just sit in the capital, accumulating gold and probably sending it back to their families or spending it on training skills. What do you think will happen when I start decreasing these nobles' estate size? That's right, I get protested out by mule characters.
No, the whole idea is a disaster.
Amazing as it sounds for me to admit this considering our complete disagreement in other matters, I'm coming to see things from Constantine's point of view. This, while having noble intentions, probably won't combat Dukes very well. Could we consider giving rulers the right to remove Dukes from their positions (not a ban, just position removal, so this side-steps the royal issue), but with a time-delay to give the dukes a chance to secede? This would allow rulers to be get rid of dukes who are inactive and not contributing, as even if they get back on in time to secede, people likely wouldn't follow them. For dukes who are active, it would create conflict that would possibly cause a large, powerful realm to fall into civil war naturally along the lines of ducal/realm loyalties. Surrounding realms could take sides or even make blatant land grabs.
