The tone of your post is pretty apologetic. You created a tool, you also have manual curation associated with the project as far as I recall from our conversations, and there's nothing wrong with any of that. Nothing really to explain. Any tool is misused when someone is malicious or opportunistic enough. No matter how many safeguards you put in, there'll be someone who figures out how to exploit it. All you can do is blacklist the assbags; doing anything else will impact the general utility of the bot. If the community in general has issues with your bot then nothing prevents them from not using it.

I'm personally less likely to vote on a post when they've been upvoted to high hell by a bot. That author clearly doesn't need my tiny vote for 6 cents but the guy down the list with no upvotes does.