Most people that are vegan or vegetarian choose that, because the ethics part of eating meat is the most important factor for them, with price and taste and nutrition trailing that.
And then a lot of those people make the assumption that everyone who isn't vegan absolutely doesn't care about the ethics of it. But that is simply not true. A lot of people, myself included, care about the ethics, it's just that we care more about taste and cost and nutrition. I love eating a good burger, or a good steak. I'm sorry a cow had to die, but I'm not sorry enough to stop doing it.
But give me an alternative that is just as good, but where cows don't have to die, and I'll switch in a heartbeat.