Has a thorough root cause analysis been done by the witnesses and/or Steemit Inc to get to the bottom of what is ultimately driving the seemingly pervasive abuse of the reward pool by some users?

To me your effort, while outwardly one of good intentions, may further obfuscate the understanding that users have of how Steemit actually works. If the platform itself was built upon allowing votes up to "X" number of days after posts are made, then the issue seems to be that this number needs to be reevaluated on a macro scale as applied to all users.

Allow me to reference the Steem White Paper for a few points to consider: https://steem.io/SteemWhitePaper.pdf

#1 - Get rid of self-voting entirely. Even the paper acknowledges the potential for abuse of this feature on page 8: "...each individual voter has incentive to vote for themselves at the expense of the larger community goal."

#2 - On page 15 it states, "Eliminating 'abuse' is not possible and shouldn't be the goal...All that is necessary is to ensure that abuse isn't so rampant that it undermines the incentive to do real work in support of the community and its currency." Well, some users have proposed ideas on how to clean up the community. So this apparently nonchalant thinking about abuse stems from Steemit's founding and needs to be reconsidered from the top. And that goes back to my initial question of what are the witnesses and/or Steemit Inc doing about it? Because you and others won't be able to effect constructive changes alone.

Speaking as a user with a limited following but that has been around for over half a year, the voting bots have been helpful in drawing attention to content that may have otherwise been overlooked. We are ultimately seeking acknowledgement and engagement within this community and I am not sure if there is a solution that equalizes the opportunity for this under the current paradigm of how Steemit works.