The carnist attempts to discredit veganism by claiming Hitler was largely a vegetarian for health reasons (which is at least partially true even though he enjoyed eating meat on occasion and had a list of favorite meat dishes)
Veganism is a moral position, in general, leads one to abstain from all animal products. Vegetarianism is about cutting out some subset of animal products (he also quit drinking and smoking). If he had been lactose intolerant (and therefore abstained from milk for health reasons), that would have been an equally bad argument against veganism.
Quick question: does imprisoning and torturing conscious beings on the basis that they are of a different taxonomic classification than you sound more like carnism or veganism? I don't know, I guess you might want to ask holocaust survivors.
Go smoke some cigarettes, unless you want to be like Hitler! Actually, you need to stop breathing, because you know who else breathed air? Hitler! This is a never-ending pit of nonsensical arguments. Do you know who else had a never-ending pit of nonsensical arguments...?