I actually don't think it has to with ETs or aliens at all. "Incarnated Extraterrestrials" I think just means "anons" or "autists".
Q is simply restating that people who keep saying "ARREST THESE FUCKS NOW DECLASSIFY EVERYTHING WHAT ARE YOU WAITING FOR" don't understand how this works, how bad this evil is entrenched, and how truly brainwashed the population is. Again 99% of the population would be in the hospital if they figured out the full truth.