That's an "interesting" ethical argument which doesn't undo the contradiction of criticizing animal abuse while contributing directly and personally in an avoidable way to its continuation. I'm sure if we apply this same logic to everything else it won't be problematic at all.

"You can be opposed to the occupation of the West Bank while intentionally buying products made in illegal settlements. Abstaining from doing so doesn't change whether settlement occurs."

"You can be opposed to slavery but still vacation at an Alabama plantation. Abstaining from doing so doesn't change whether slavery occurs."

Before you go for the obvious argument, I'm drawing no equivalency of any kind here other than using the same logic. It's obvious that these arguments are morally bankrupt and only serve to allow the speaker to absolve himself of contributing to harmful systems when he could trivially avoid doing so.

This seems like a ridiculous point for me to have to make to an Anarchist, to be honest.