I was a vegetarian for like three years before I realized that it was dumb.
Animals are not people. This is something that vegetarians don't fully realize, I think. Animals have nothing to live for, except for eating and sleeping and maybe having sex. Animals do not have emotions, or at least none beyond the most primitive of the primitive. If I kill an animal in a way to ensure that it does not suffer, the animal is unharmed. Yes, unharmed. Sure, now the animal is dead, but of course being dead is not painful. You're just... dead. Contrast with the act of killing a human, in which the enormous potential the human had for the rest of his/her life is now completely lost. But an animal has no potential to do anything much - it's an animal. Additionally, there are no grieving animal widows, contrary to what Bambi might have you believe.
Basically, the way I see it, animal rights are kind of a weird, misguided idea perpetuated by people who identify really strongly with their cats, or people that watched too many talking animal cartoons as a kid, or people who spend a lot of time outdoors with birds and such... you know, "animal lovers". These people, it seems, know in the back of their mind that animals don't really have any capacity for emotion or rational thought, but still have deluded themselves into thinking something like, I don't know, that their cat is attempting to communicate coherent messages with its meows. And okay. There's nothing wrong with a bit of make believe, it doesn't really affect me. But when these people affect politics with their misguided ideals, it really bothers me. People should not be donating money to stop dogs from getting euthanized by animal shelters, or stopping people from dumping oil in the ocean and killing fish, when that money could go to helping all the starving people in Africa, or child laborers in foreign countries, or victims of genocides. You know, humans in peril. I really think we should first make sure that all the humans can live more comfortably, then we can move on to animals. And of course, this will never happen.
Sure, there's no real reason to eat meat, other than the most shallow excuse of "it tastes good". We could all go without the delicious, mouth-watering, succulent, taste and use some other method of getting our protein. But there's also no reason not to. When one becomes a vegetarian, they are not doing so because they believe that their actions will have a tangible effect. One more person not eating meat will not somehow decrease meat production, or bring animals back to life. No, they are doing so because they believe that the movement to make as many people as possible vegetarian, and thus, decrease the amount of killed animals, is a fruitful one. Maybe they hope that their vegetarianism will influence others, or perhaps they just feel like eating meat isn't consistent with their philosophy. (Or maybe they're Hindu.)
But the vegetarian movement is not worth following. Human lives are worth infinitely more than animal lives. And even if the vegetarians win, and in a hundred years no single person on planet Earth eats meat, then what have we really accomplished? Animals will still be killed all the time. In their natural environments by predators, by you when you accidentally step on a bug, by you when you set up traps in your house to kill mice, by hunters when it is deemed that a certain species' population is too high, by harvesting equipment that collects grain to eat, etc. Humans will always be killing animals, and more importantly, we will probably always be killing other humans. The latter is what we should focus our efforts on stopping.
edit: wow this post is really fucking long/poorly written
edit 2: also, any vegetarian who claims that meat substitutes are just as good as the real thing is a liar (or somehow has defective taste buds). those things are disgusting. even when i was a vegetarian i got by on eating mostly fruit and dairy and such.