Two of my sisters are vegetarian, one is very close to vegan. It's nothing to do with animal cruelty thing for them, they just think eating meat is gross. My younger sister says "you wouldn't want to eat their butthole or their peckers or their eyeballs, why would you want to eat any other part?" I guess it makes some sense.
But with two vegetarians in the house, growing up we had a lot of vegetarian dinners. Lots of places besides soy to get protein. We never ate soy anything. We had chickpeas, peanuts, lentils, broccoli, avocado, all kind of beans. It really isn't hard to get protein. Vegetarian chili is still one of my favorite dinners. Ground beef is good in it too, but it doesn't make a ton of difference to me.
All that said, I still prefer meat.