It has to be because of either conscious or unconscious guilt, right?

Nah, that’s more reflective of what vegans would like to think their motivation is. I think it’s a combination of toxic masculinity and class bias. The former, that stereotype of the “my food poops on your food” mentality, rah rah hunter man eat meat be strong hairy caveman. The latter, that goes back to the feudal era when the peasants subsisted on root vegetables and garbage cuts of meat that had to be boiled for three hours just to be able to chew it, while the nobles and aristocrats feasted on rib roasts.

So for them, veganism means being a poor soy boy. And you know how reactionaries get when anyone suggests they reconsider how they see themselves vis a vis class and masculinity.