Understand that you don't get to pen the ethical frameworks for the world, only for yourself. Even in ethical frameworks where "consent" and "killing" are given extreme weight, there are always other factors... And under most of the foundational ethical frameworks (Utilitarianism and Natural Law Theory come to mind), the argument for necessary-veganism is unsupportable.

So if you want to hate meat eating, say "I think it's wrong to eat animals" or "my morals don't allow it". Don't tell people who eat meat they don't care about ethics, because that statement is simply dead wrong.

Particularly when the “sacrifice” is for the trivial reason to satisfy the killer’s taste buds

My biggest complaint about proselytizing vegans is the way they oversimplify the equation. Like every single person who ever eats meat for any reason stops with a fork in their hand saying "Is this bite of food more important to me than murder? YES IT IS".

To violently take another’s life “because it tastes good” and then go through such convuluted reasoning to justify it is very puzzling to me.

With all due respect, reality is not as simple as you're making it out to be. If you cannot see that there's more to the discussion than "meat tastes good" and "animals don't want to die", then nobody can help you. But pretending that people use convoluted reasoning to justify it is an ignorant take, whether willful or out of being blinded by your own zealous position on the matter.

It suggests a lack of empathy that seems to be endemic in our society

You do understand that from a psychological point of view, human empathy and animal empathy are different factors and rationally exist in different amounts. Honestly, my personal take is that zealous vegans show less empathy towards fellow man than other people. LOOK at the way you're thinking about supermajority of humanity? Why should I not see that as a lack of empathy as well?

And for that matter, there are several empathy-related disorders where a person's mispaced empathy goes so far as to affect their relationships and quality of life. And again, that's only for that rare person staring at meat on a fork commenting about how murder tastes good. The ones who simply categorize animals or plants or insects differently from you in their empathy don't suggest anything of the sort.

Serial killers love to kill, don’t they?

Tell it to me straight. Are you so far gone that you cannot understand the moral, ethical, or psychological difference between being an actual serial killer and simply not being vegan?