A trace amount of animal fat makes veggie heads (carnophobics) go bonkers.
They really are a hyper sensitive bunch. A bit too much on edge it seems.
Hitler who was a bit unhinged went vegetarian later in life. Although the vegetarian part does get disputed. ( being unhinged doesn't )
This is worth a look :
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3466124/
From the "Conclusions" section of the above link :
"Rather, our results are more consistent with the view that the experience of a mental disorder increases the probability of choosing a vegetarian diet, or that psychological factors influence both the probability of choosing a vegetarian diet and the probability of developing a mental disorder."
Finally, when I see veggie heads ranting it does remind me a bit of the character Jack D. Ripper in Dr Strangelove ranting on about "bodily fluids". Maybe that's just me ...