@Orion: Well we sort of need to to not die, for a start.
But meat, as a foodstuff, has it's appeal. for a start it tastes good. Or at least it can - it depends on what you do with it. Some people just like the taste of meat on it's own, but I think it's best when you prepare it a little bit.
There's also the tactile sensation - chewing meat feels
good. It's a very solid food, and reacts more interestingly than vegetables and fruits, I find.
Finally, our bodies crave it, so our brains reward us for eating it. The protein in red meat makes men in particular just feel good about eating it.
In short, it's largely biological. We're built to eat meat, so we do. Though I have met people who simply don't like meat. I had a friend who hated the taste of it, and so became vegetarian.