Don't think blood moon is being grinded/farmed. Blood moon/scorpion eggs are an occasional 'wow' find when regularly looting and a good reason to stop by whorehouse. You'd be insane to start grinding it. Reward is too low.
Grinding/farming generally happens when the reward vs time invested balance is off. The returns are so high that players are willing to cope with hours of mindnumbing PVE. Idk if you ever went on a BoS hunt pre-NPC buff. Incredibly boring, but in an hour of complete boredom all party members would have an mg42 or TP with some PA pieces on the side. You can still hunt BoS now, but it will take far more effort so people don't bother.
Blood moon: strong, unattractive to farm due to bad time/reward ratio: not farmed but still cool to find.
Nuka caps: strong, attractive to farm due to good time/reward: being farmed.