I'm pretty sure that the cosmodrome's been irradiated, meaning that it's not exactly safe for guadians to be present. Guardians with radiation poisoning can wind up in a pretty much never ending death loop. Resurrections, from a lore standpoint, don't cure things like this. I believe it's talked about both in the Ecdysis lore book, and the Drifter talks about it. He said that in the dark age, guardians would starve to death and be brought back still hungry.