I totally agree with your first paragraph, it is the responsibility of everyone with stake (or delegated stake) to take action. The conflict of interest for us lies here: If we downvote a user who used any or several bidbot services, it may look as if we are trying to discourage users from using a specific bot instead of OCDB thus wrongly making us look like "unfair players engaging in dirty competition", when in reality we don't want to compete with anyone, just try and distribute stake in a fair way.
We are already seeing bots taking back their vote on abusive posts (including ocdb, we already took back some votes) and hopefully every bot will begin doing this so if/ when the scenario you mention in the third paragraph comes into play, we are not forced to take action. If it does happen, as you say, it will be on everyone's interest, including us, to dive into downvoting those posts.
Thanks for your input and as a major OCDB delegator backing the decision of downvoting circle voting farms.
Yeah I understand what you are saying about downvotes being used as a malicious competitive tool and I'm certainly not in favor of that. Anyway thanks for taking the initiative on this now as you have and I'm sure we will learn more going forward.