Whether or not you love in a food desert, the result of your actions are the same. You may have no choice, but you're still financially supporting animal cruelty.

The action is cruel, not the people committing it.

That is no excuse.

You don't sound like you'd accept anything as an excuse, so that's really not saying a whole lot...

You can move.

You don't need fresh produce to not eat animals. Beans, whole grains, potatoes, canned vegetables are the cheapest foods around.

These people already weren't eating fresh produce, so why would they need fresh produce to swap meat for beans?

Though I think debating your idea of exceptions is a red herring unless you yourself are vegan and already concede that pretty much anyone reading this on HN should be vegan. But you probably don't grant that, so there's no need to go line-by-line through your idea of the exceptions when we can discuss why you still eat meat without making excuses for other people.