Doubt it, we're omnivores, hunting comes naturally to us, therefore eating meat is fine.
Yes, there is little else which compares to the visceral thrill of clam hunting. It's in the blood. Furthermore, I suspect that Mind Flayers also love their fair share of clams and other bivalves, being that they have evolved with those octopus-like tentacles on their faces ... perfect adaptation for eating clams and mussels.
