by problems with witness i mean it would be easy to implement change in hard fork to reduce value of multiple consecutive voting and selfvoting would save a lot from reward pool and give value to content creators and incentive's searching of content as is what platform was designed for also the 5 minute window which directs most curation to user all easy fixed
by selective moderation is the fact pushing of scam ICOs referral links and plagiarism by stake holders and witness gets receives no action multiple other accounts also for whatever reason