The only problem I have with this is that if we did manage to tweak algorithms to skew positive instead of negative, then everything would be flooded with cheap low-effort positive stuff instead of cheap low-effort negative content.

For sure it would be an improvement is the constant flood of prattle had a more positive tone, but I don't know how much it would help, especially with what passes for "positive" or "wholesome" or "heartwarming" anymore. It would just be variations on, " School kids raised $50,000 to save 10 orphans from the orphan-crushing machine" all the time.