HN sure doesn't want to hear it, though.

The reason people get so upset and angry about vegans, the reason they keep making fun of them, is that they do know that they can't form a coherent argument for why they are wrong.

There is no morally coherent argument for eating meat beyond "I care less about the suffering of animals than I do about my own pleasure". That is a valid argument you can make, though, but most people do know deep down it makes them look bad to make that argument, so they will instead just attack vegans for being annoying rather than face up to the consequences of their own choices.