The whale dependency has been a problem for years at this point, but I do think it has grown increasingly worse as of late. Many communities, big and small, would simply collapse without it. In smaller communities the argument of less interest being present due to niche subjects is valid, but the bigger communities relying on them does show a problem.
OCD has a generally decent idea towards who gets upvoted and how often: two times a week is the max and there was (at least when I was contributing) a look into whether people were considered over-rewarded and held their HP or not. The dependence is still very much there though within the communities under their incubation.
Appreciator is definitely a problem because they're clearly throwing daily votes at a group of people that barely hold more than 800 HP but are making 1k Hive a month from those votes. There's definitely no regard for the posting and curation habits of the person getting those votes.
No idea what the solution is here. Tighten things up too much and people leave, don't tighten things up enough and the dependency continues/worsens.