That’s such a cop out. Arguments from nature can be used to justify anything and they’re just ridiculous puppet shows anyway, nature is many things but you have moral agency.

If a rapist mounts that defense? a whaler? someone who runs a puppy mill? someone who beats their children or spouse? an abusive boss etc what would you say to them?

It is dishonest to yourself and cruel to others to behave in a way you know is wrong because it is, as of yet, still socially permissible to do so. It’s like being a homophobe in the 2000s waiting for gay marriage to be legal before they’ll stop shouting slurs at couples they pass.

edit: also none of us are great moral crusaders. People realised this shit thousands of yeare ago, probably much earlier too but we don’t have records. People did this when it required sacrifice. Going vegan is easy now, there’s a wealth of information on how to eat well — both from a hedonic and health perspective, can find off the shelf products most places, it’s easy to find plant based options eating out in most places, workplaces and events tend to be accomodating. Literally the worst consequence is seeing people online post stupid stuff.

I am a human garbage fire, I can be lazy, I can be selfish, I can be abrasive and impatient, I phone it in at work sometimes or tell small lies to get my way/exaggerate difficulty to avoid work. If you think you have to be some paragon of morality to go vegan you have an incredibly warped view of the average vegan and your own capabilities. It is literally the moral baseline and down there with not snatching shiny objects.