I love your choice of words!
"Force", "seems unfair", "not very enjoyable".
What about MY rights, or the rights of the other players at the table? Do they disappear as soon as the munchkin enters the room? We do not enjoy that style of play and under no circumstances should we be "forced" to endure a game we "don't enjoy", merely to placate the munchkin. That "seems unfair" - to us. If he likes that style, let him make his own campaign and collect his own group of munchkin friends to play with. We'll do our own thing, both groups will be happy, and we can meet together on a more neutral ground to discuss gaming as a whole. To each his own.
If he insists on staying, though, I am going to do what I can to make sure that his style of play affects the enjoyment of the rest of the group as little as possible. That is my right as GM, and if it means one person's rights get trampled in favour of the majority, the door is always open for him to go and do what he pleases.
So ... he does have freedom, just not freedom to wreck the enjoyment of the rest of the group. If he insists on that, he has the freedom say whatever he wants as he is getting shuffled out the door.