[jmye]

I think it frequently depends on the thread you're reading and your expertise in that area? There are a few things I'm intermediate to expert in - frequently the quality of comments in those threads is quite poor, but the noise & upvote-y memes look like signal in those areas, so it may not look as bad from the outside.

On the other hand, there are a number of things I'm not very informed about, and I do frequently find a few posters in those threads who seem to have very insightful things to say, but I'm not sure if they actually are (sometimes you can tell from replies) or if it's just because I'm a neophyte.

Which all goes to say I don't know if this system would really help, or would just turn into bad opinions getting even more support because the crowd-sourcing is coming from others who don't have the necessary expertise to evaluate what's worth listening to.

[jonathanstrange]

I don't see how it could work, for the reason you lay out. It's one of those tools that wouldn't be needed if it worked and can't work if it's needed.