Celestia is the only one with give up? I'll consider that a bug.
As for being a drone, it's not a beneficial transformation. It's becoming literally brainwashed.
I'd like to also ask what you think Cadance is not adding worthwhile?
Well, she doesn't have anything that allows her to hit hard. Her healing ability is just that...healing. And she has a double attack that she doesn't gain until later on. And even then, you can bearly use it at all. Either because you are using magic that. Most of the time, I am just spamming Celestia's magic to kill everyone anyway. The only reason not to lose Cadence is to make sure that at least one other pony is not fully captured.
I still say that you can for the most part use the drone ability after you beat the first level. Becoming a sort of super solider.