I think I don't have to explain why and how peer review works in scientific journals.
While I think one user - one vote fits proposals where no long and higher education is needed pretty well, I see some downsides on scientific proposals. Esp. regarding questions in a BETA period.
I watched for some time the astronomy and philosophy BETAs here and a lot of questions are more on tricky black holes, dark matter physics, religion, god, death and speculative subjective reasoning than "real" astronomical and philosophical questions discussed in scientific journals.
My expectation is, that users with higher reputation due to good referenced answers and logic reasoning and higher vote count (for example, rep higher than 1000 means 2 points per vote (up/down) could much better regulate quality and development of such scientific BETAs than the mass of interested, but often without deeper background knowledge equipped, standard users.
Basically this is the function of peer-reviewers, and history has shown, that the scientific community needs them. Don't mix up peer-reviewers and moderators. They have similar functions, but not the same. A moderator has to filter and regulate, a peer-reviewer to filter and highlight important information/questions.
Also this might be a option to stop dividing of proposals in laymen and few experts - only experts (like physics.SE - theoreticalphysics.SE) I think such developments are a effect of this too democratic, linear voting, and reputations system for such proposals.
There are probably some downsides. But with so many different proposals in content, I strongly believe one voting and rep system can't fit all. Maybe it's technically not possible/feasible to set up different systems (I don't think so, it is basically just numbers) or Stack Exchange operators want that everybody doesn't have to be aware that his votes counts differently on different sites?
I don't think that more previliges of higher rep users compensate the curiosity for speculative and sensational questions. These privileges work mainly to filter out very bad questions, and this works. But a higher voting strength for higher rep users would highlight really on topic and interesting questions more.
It would be perfect if high rep users could decide by clicking from e.g. 1-3 time on a upvote arrow, how much votes they want to give a basic question, how much a very good on current research.
Plz give a comment or link to former similar discussion when downvoting, a downvote doesnt tell me whats wrong with this question, despite you dont like peer-review, which obviously works in scientific journals better than highly democratic systems like arxiv.