The universe and all existence might be destroyed by the Terran's, but the Drengin caused it to happen! When you think about it, we get blamed for a war the Drengin started! It reminds me of a time when I was little and got punished for something I didn't d... Forget it. Lol
If I remember correctly, the drengin caused the Dread Lords to come back no matter the consequences, what happens next is similar to how the US Russia and China became super powers after world war II. And you can't hold that against the Terran, even in their ignorance of the future. It seems living another day is all that matters. Even the Yor would try preserving themselves.
So maybe its not ALL the Terran's fault, its the Drengin AND the dumb Thalan for not coming back in time fast enough.
I'll imagine the Iconians do something useful to help stop this, them being present near the dawn of all creation should count for something. Lol.