With all my respect but it looks like you are focused on a problem with is not exists. In "open systems" (with really don't exist) it is easier to get control over. You just take 50% nodes and that's all. No license, no control. If license is given by organization it is controlled and we know who gives license and to whom. In that point it is hard to take control over the system.
If the blockchain is large and popular, then taking over the majority is not very easy and very expensive. And if someone has captured 51%+ in the top blockhains, then it is more profitable for these people to continue earning than to sabotage.
But it is the same for the licensed system to. The profit is more important than control just for control.