Actually celery and all other vegetables only raise your purity which is separate from morality, so you can sacrifice a bunch of people but be very pure and basically turn into a pale-ass vegetarian vampire.
Purity kind of tracks with a vague idea of “health” and “decadence,” so doing things like eating rich foods (meat), making lots of money from your shops, or getting drunk a lot will lower your purity. On the other hand, eating vegetables, drinking clean water, or lowering your prices to make less profit will make your purity go up.
So if there’s a political statement there, it’s that eating meat is for gross rich people? It doesn’t track well with anything really. Especially since they combine money and meat into one scale.