Man I had to rephrase this a dozen times and I still don't have a good way to communicate what I'm trying to say.

The goal of this kind of callout is to make vegetarians, people who already value animal welfare, aware that they may still be contributing towards animal cruelty. For example, I was a vegetarian for years and then got rocked by the realization that, "oh wait, vegans aren't just crazies that I can blow off, it was me who was ignorant the whole time."

So I anecdotally assume that a huge percentage of vegans are vegetarians who went from thinking "vegetarians and vegans are basically the same, besides vegans taking the idea too far" to "oh wait there's a huge important difference between the two." On vegan spaces, people often joke that "bullying worked on me lol" because the gentle approaches are easily ignored, but the really blunt "your actions don't align with your stated ethics" is really difficult to brush off.