Disenfranchising everyone at once beats disenfranchising enough to be a problem but not enough to motivate a solution, which is what the drip feeding achieves.
That's the whole point of doing it fast, otherwise yes they will attempt to slow things down so they can take advantage of the intermediate state where some are still standing, temporarily, to get rid of the others. And that is very much what a lot of the current pausing noise is in aid of.
Well, they are monsters, but the reason they do it is because it's kill or be killed for them. You have to eliminate threats before they eliminate you.
And believe me, LOTS of people will want to depose a world dictator.