The short answer is: because I can’t imagine living any other way.
A bit longer answer can be summed up by this awesome infographic (click on the graphic to make it readable and don’t look at the comments if you’re sensitive).
The real answer is a lot longer and would make me cry if I went on and on about all the reasons. Basically, I love the world and life. I can’t understand why I would want to hurt another being for a reason so selfish as “it tastes good”.
Our world is beautiful, but it’s getting uglier by the day. Animal agriculture is one of the major things trashing our planet. No, the world isn’t going to end if everyone keeps eating meat. But we might.
And even if we move to Mars or find some other high-tech way to survive on a depleted planet, I know I’ll miss the trees. Grazing by “food” animals is a major cause of deforestation. And we’ll all miss clean water when it’s gone. One of the biggest pollutants is run-off (i.e. shit) from factory farms. I like being able to breathe, and though cow farts sound funny, the impact of methane on our atmosphere is real. And that’s not counting the air pollution from the massive amounts of transport the animal agriculture industry requires.
I just don’t understand why these things don’t matter to more people.
Maybe you think I’m too sensitive, but I like to look at the world with my eyes open, to enjoy the beauty before it’s gone.