are vegetarians more ethical by not eating meat?

[littleendian]

I don't think you've spent much time looking into this issue if you think that vegetarianism is less harmful on the environment, or that eating meat has anything to do - with anything more or less- than feeding ourselves.

Look into it and you will find that funneling our grains and soy through animals before consuming it is a vastly less efficient use of the limited ressources (land, water) that we have to grow crops than if we consumed the crops directly, not to mention the by-products of animal agriculture like methane.

I think that what's probably happened here - is that you've made generous allowance for connecting things like abusive (in the environmental sense) and unregulated battery farming with an omnivorous diet - as though the one does not or could not exist without the other

If every person on the planet would want to eat even half the amount of meat that we consume in the industrialized countries (and with a steak in your mouth its hard to convince them otherwise) then this would indeed be impossible without extremely intensive animal farming, and if such enormeous stress is put on any system it will most certainly have little concern for the well being of its "product" or the environment.

while simultaneously whitewashing the very salient observation that of the vast swath of things -we do- on this rock, agriculture probably has the best chance of "destroying the environment"- all for some greens and beans.

This is an invalid all-or-nothing argument. Just because our very presence on this earth is damaging the environment it does not follow that we can't or shouldn't minimize this impact. Some of worst mono-cultures on the planet are the soy fields in South America, and this soy is produced to a significant percentage (85% is one number floating around) for animal feed (because soy contains more protein than grass/corn which makes animals grow faster which yields bigger profits).