It might be extreme, but as far as I know, I also don't vote for witness anyone who operates a bid bot. These people aren't propagating the chain.
I actually think that witnesses should identify as operators/delegators/supporters of bidbots. Perhaps then they will be forced to remove their 'Cone of Silence' between them.
You can check. Its all on the Blockchain. Using the tools at steemworld.org you can see who is delegating to who. 2/30 witnesses (I've checked 5 so far) delegate to bid bots. They're getting their witness vote from me revoked today. :)
I've now got six witness votes ready for the taking... After going through all my top 30.
some delegate through other accounts to potentially or have something to do with the development teams