Or perhaps it's kind of how the human race (among others) has survived since the beginning of time and it's deeply rooted in us on an instinctual and primal level. There is absolutely nothing wrong with killing an animal for food so why would there be an ethical dilemma about it?

People don't have ethical dilemmas regarding their own survival. Comparing eating food to survive with materialistic possessions is pretty ridiculous. You don't have to be a vegan to realize that the processing of animals the way we currently are might be unethical or cruel but that has absolutely nothing to do with whether or not I consume meat. They are entirely unrelated and that is why most people make fun of vegans.

People don't scoff at vegans because they fear what they don't understand, that's thinking too much into it. We have survived this long eating meat just fine (and so have the things we eat) so that clearly isn't the issue.

Giving up eating meat in some sort of social crusade against mass production is just a very silly way to go about your goals, that's why we scoff.