Medieval Feudal societies were full of politics, intrigues and conspiracies... "Be Trusting" was not the best quality on courts.
If group of Rulers would decide to create common Guild they would definitely never trust each other to the point to grant powers to one of them to overrule them all - we all know the results of making "the one ring to rule them all"
Well... it was absolutely unnecessary to drag "don't like - don't play" argument... I was only benevolently suggesting Feature that can improve the game.
Simple not implementing it if you dislike it was more then enough...
