It's a novel idea, I can certainly see the nice implications of it, but it also seems incredibly excessive. Would you really going around flagging every user you see on a trust system? Or even enough users for the system to be moderately effective? And then expect many other users to do the same?
I honestly don't think I'd use it, blocking people is enough for me.
I agree. I personally found the system was far too addictive, in the Cookie Clicker kind of way of "bigger number = happy". I sometimes find myself missing it almost, only to remember that it's worthless.
It also means I can more freely share my actual opinions, without that reflecting on some sort of global score if people generally dislike said opinion.