Why are men so proud of not eating vegetarian food?

I frequently encounter men who do not like vegetarian food. I'm not talking about just quietly not liking vegetables, which would be fair enough. (I know people who don't like fruit and even people who don't like water, so there's really no limit to how basic a food or entire food group might be and there exist people who do not like it.) I'm talking about men who go on at some length about how they like meat and only meat and bring on the meat, and imply if not state outright that a man who likes vegetables excessively is less of a man. One person I know who speaks like this even loves vegetables and vegetarian food, if you judge by what he enjoys eating and not by what he says.

Each man needs to have a certain critical mass of masculine signifiers. I approve of this; I am comfortable with men having a certain amount of masculinity. But many of the masculine signifiers require some kind of work, or sacrifice, or are painful in some way. Here are some: success, ambition, stoicism, being good at sports, doing the iron man competition, having big muscles, helping you move furniture, not crying when sad, pretending not to like delicious umbrella drinks, etc. But eating meat... there's one that requires little sacrifice (on the eater's part, that is.) Liking meat comes naturally. And hey, maybe many of the other masculine signifiers do too ... but most of them require work.

This reminds me of lyrics from one of my favorite songs by the inimitable Rev. Fred Lane:

From "The Man With the Foldback Ears"

(Song has a spaghetti western feel to it)

"A man wants to smell like a man

To crush a tin can in the palm of his hand

This...

(sound of can being crushed)

...is a man."