I think OP is seeing the wrong correlation in a very not-all-rectangles-are-square sort-of-way. The correct attribution being the type of people who engage with the culture war (with some ties to masculinity or status).

My parents eat way too much meat (even though they often get tired of it, especially when it's primarily cooked meat) and are the type of people who would say with a straight face that a side of edamame (soybeans) is basically HRT. They do eat vegetables but it's still very meat-and-potato centric, less vegetable if I wasn't always pushing for it (including proving to them that roasted carrots are good).

im bisexual and im middling to positive on veggies, and so is the other bi person in the work chat who responded lol. most of my friends are queer in some way, and it did trend towards the heterosexual/hetero flexible friends disliking vegetables more. the funniest correlation here is that both of my pansexual friends have major food allergies lol