There are, you'll be pleased to hear, many vegans with stronger ethical arguments than "meat is murder". Such as, in summary:
* unnecessary extreme suffering is unjustifiable.
* some non-human animals (notably the ones we eat most of) are as capable of suffering at the physical level as humans are. We shouldn't discount their suffering just because they aren't members of homo sapiens.
* factory farms raise most animals in conditions of unnecessary extreme suffering.
* therefore, it is ethically wrong to eat those animal products.
(This is actually an argument for eating humanely-raised meat instead of veganism, but finding verifiably humanely-raised meat is difficult enough that I'm not sufficiently interested to bother, and there are practical advantages in eating a predictable diet. So I just eat vegan.)
By the way, I hate the federally subsidized crop situation too. I wish I could do something substantial about it. It's disingenuous for you to say that vegans are uninformed about health issues or industrial practice or the farm lobby just because they don't "focus" on it; that doesn't match my experience of other vegans at all, and it's obviously untrue that someone can only pay attention to one issue.