If Scorned gets the chance to realize someone is suspect, then frame them and push them the following day, then sure Scorned can just attempt to get out baddies. What happens most of the time is that they get someone killed wrongfully and their frames messes with invest results making the BD waste time - that is not in BD’s interest.
In the same position the Mercenary can block invest classes and makes people waste time by occupying them. True their shield is mainly a BD benefit, so I’ll give you that they are inclined toward BD, but not in the same way that say a Sellsword is to Evils or even Inquisitor.
Alchemist’s inclination toward BD is only because BD wants to strong arm alchemists. If a player is bleeding and an Alch is not healing them, then BD is inclined to believe they are aligned with evils and therefore often kill them in the absence of a better target.