I think the point is that there are some opinions that must be based on objective truth (whatever that is), for civilisation to remain stable. For instance- accepting the fact that our activities are causing climate change is something that has the ability to affect our chance of survival as a species -etc.

I don't think the author means that _every_ belief held by any person must ultimately become "objective" (and, therefore, aligned with that of all the rest of humanity). For instance, I don't see how it is bad for human civilisation if I think I look ravishing in red, whereas everyone else thinks I look like a pillock.