Because people can make their own personal choices, whether they want to be vegan or not. But then, other people just don't respect their personal choices and beliefs, and mostly more on the importance of animal cruelty and torture, and they'll do many unnecessary things to make people become vegan, like yelling at or judging harshly at a person just because he or she ate a beef burger. And eating meat is totally normal. It's part of the food chain. Other natural predators eat meat too.