In a perfect AU (and SE in general) world, I believe, you would want the most number of users to participate in the most number of question. This means taking the most of knowledge from the most of users, leading to an almost perfect Q&A voting system (a kind of knowledge democracy).
Thus, you want most of users to go through as much questions as possible and cast their votes with respect to:
- quality of question (up/down)
- best answer (up/down)
However, this is not a perfect world since we are contained by time. Thus, the actual system is rather imperfect although still very useful in most of the cases.
The point of this question is therefore aiming at the theoretical, perfect-world level. I rephrase it: would it be ideal for the optimal state of AU that all users, in accordance to their capabilities (expected to be reflected by reputation points), participate in all existing and future threads?
PS: the question is rhetorical. Not that I have the experience to do so.