"The issue is: current curation/reward system simply does not work. "

I think this is a big part of the problem. The curation system should encourage upvoting others more. However, from my own observations, it rather strongly encourages upvoting yourself or creating bot nets. Maybe adjustment to the 30 minute rule is necessary, or maybe curation simply needs to have its overall coefficient reduced.

Either way, curation is hard to abuse and I think it should be rewarded more.