As long as there are people selling votes, and votes remain in demand, people are going to buy them. Quality is not a factor when it comes to self-promotion - only money.
Giving away control of your stake in Steem Power carries some natural consequences with it. You would have done well to understand and come to terms with this fact BEFORE you made your decisions to go forwards with your plan. Now, however, bots are here and they seem to be here to stay. Now, bots are out there putting the kabosh on other bots' activities - and it's really making the whole environment here seem a bit strange.
Of course, even stranger than the behavior of bots is the behavior of people - the values that govern our actions change on a whim, and that is a fact. There is a bit of psychology/sociology involved in predicting all of the possible behavior patterns, differentiating possibilities from what are the most likely probabilities, and then implimenting changes or 'rules' to re-assert your control over the outcomes. This is social engineering at its' finest - and I find it to be very interesting. Here on SteemIt, we have our very own little laboratory for social engineering experiments. And, if you do not know what you are doing - you won't even know how to begin to analyze your results.
Placing rules and conditions on people using and/or abusing your bots is something that will require full-time monitoring on the part of the bots creator. Now that you are realizing the time involved in controlling your own creation, you seem to be having some regrets. Well, it is never to late to change course and start over again. Maybe there is a way to create better, more intelligent bots? IDK - I don't play with bots very much. I'll use them here and there for a resteem or an upvote, because they are there to be used and I have a tiny bit of money to use on them.
Certainly, losing sleep over this situation is not a good circumstance for you. Now I think I understand why God had to send the great flood to wipe out his corrupted creation and start over again...