Society wide change is always hard, and meat is way too cheap (considering its environmental impact) to provide the economic stimulus for reducing the amount of meat in ones diet. Learning to cook vegetarian dishes is also non-trivial (although not too hard of course, but a barrier nonetheless).
For people over fifty meat is also an indicator of welfare. Especially for people whose parents didn't have the luxury of eating meat on a daily basis.
Fortunately, the shift to less meat is unmistakably happening, and has been gaining speed in the last few years.
> vegans and vegetarians are substantially more likely to be thin and, well, less traditionally manly, both in appearance and in values
I can point you to many fat vegans, and I've heard this 'need meat' BS from guys who were literally 135 lbs, soaking wet, so.... exactly this kind of attitude that 'meat makes you manly'.
Who said that I disagreed with those values, that is a poor assumption on your part.
They ain't cheap (and if you buy one, they are daunting to cook - because you know if you screw it up, you've just wasted $100-200.00).
Ground beef, or chicken, or pork - those are all still very inexpensive; though pork can get pricier for certain cuts - mostly it's still very inexpensive.
But damn - if you've ever smoked a pork shoulder and made homemade pulled-pork sandwiches - you know there's no substitute for that.