The problem is that if people can profit from only the value of the bot's vote, vs from the added visibility to their post, then that encourages spammers to make a bunch of low effort, low quality posts just to grab some profit from the bots.
By setting the fill limit to 1.1 or 110% (in addition to setting the min_post_age to 20 minutes) I believe that it will help prevent this type of spam - since it will no longer be profitable - and encourage promotion of actual quality content.
I definitely plan to publish this information on steembottracker.com in the near future.
Yes there can be more indirect value that comes to posts after a vote comes in.
Ultimately the market will determine how this plays out. As long as bid bots are profitable more will be added and when they are not profitable people will stop using them.
Interesting perspective you had earlier with the idea that your blog on steem is a business rather than thinking of it as another social media site.