By definition, every single person, without exception, who goes vegan ate meat their entire lives. That point at which they went vegan was the moment when they stopped eating meat. I, myself, ate meat my entire life until I went vegan.
I'm not asking you to abstract outside of yourself and "become vegan," as though if you're not born vegan then you cannot ever be vegan. Everyone who is now vegan was once just like you - there is nothing metaphysical about this.
It seems to me, then, that those people who would employ this excuse are in fact saying the following: "Regardless of the validity of your argument; even though I do agree that our treatment of animals is utterly atrocious because they do in fact suffer and feel; although we as a species do owe direct moral duties to nonhumans, I refuse to alter my simple habits."
Technically, it's not true that every single person who goes vegan previously ate meat. My parents were lacto-vegetarians when I was born and I was a lacto-vegetarian for a bit over 20 years before I went vegan.
Sorry to nitpick, but you'll have to replace "meat" with "animal products" to make this apply without exception.
Well... I suppose there could be people going vegan for the second time.
Fair enough GLT. Good point :)
Well put. This "justification" gets so frustrating, for all the reasons you mention. It is simply not a justification!