For clarity here - I eat mostly vegetables these days - I grow a lot of my own food, chemical and pesticide free (NOT LIKE THOSE CORPORATIONS THAT GROW GMO SOY FOR VEGANS!!!) :)
But I believe there are reasonable and ethical ways to produce and consume both animals and plants, and that the answer is the same in both cases...
The big battle is between corporate agriculture selling a mass product that disrespects the environment, applies chemicals, and produces substandard food, and human-scale agriculture - locally grown, seasonal, respecting the organism, and gown sustainably and ethically, reducing waste as much as possible.
If you are going to eat pig, for example, it should have a natural life, running semi-wild in forests, rooting for anything it can find to eat, and it should be eaten snout-2-tail, not just some filets cut off and the rest thrown into the garbage.
Similarly, plants should be grown in sustainable ways without insecticides, pesticides, GMO, and they should generally be grown on medium-sized holdings with great ecological diversity in a way that doesnt harm the soil or the water.
Both of these are best satisfied together - for example, chickens make great pest-eaters (and fertilizers), and every pond is better with a few fish in it.
But rather than throwing the chicken in the garbage when its life in the farm's ecological balance is over, it should be used, not thrown away like garbage.
But yes, we need as a society to eat less meat. And of the meat we eat, we need to ensure that it is grown or collected sustainably.
To believe that corn and soy monocultures are the solution to all evils.... Nope.
So lets abandon our labels and religions and work together to build a better world for all.