I believe part of the issue is the new voting power equation...for instance, prior to the last HF, I was using SteemVoter to cast votes automatically for me on the accounts that I thought put out good content...if the post didn't gain much and the curation reward was small, it didn't matter...now that the votes are worth more, and voting power takes longer to replenish, I have shut down SteemVoter and spent time casting votes manually...which means quite a few of the people who used to get my votes, aren't getting them now...they're going to better content because I have to take time to make sure I want to spend my vote on that post...I'm guessing I wasn't alone in making this change...that's my take on what's happening...because I noticed quite a drop off myself, and only one or two bot votes per post.