>...and put them in a frame of mind to consider that they might be wrong.
You are entirely correct, but I think what GP is saying is that there's a very specific kind of person who goes from being insulted on the Internet to open to reflection and it's not most people.
That's true when they're reacting to criticism from outside their tribe, but "classist as fuck" (and the whole rest of the rant) sounds like it comes from the same perspective that people were trying to inhabit by buying into the "rescue ugly produce" story. This creates a "the calls are coming from inside the house" moment that makes people nervous that they're on the wrong side of the issue, so when the issue comes to their doorstep (somebody is marketing some "ugly produce" product or service to them) they might look into the specifics instead of blithely accepting it at face value.
You are entirely correct, but I think what GP is saying is that there's a very specific kind of person who goes from being insulted on the Internet to open to reflection and it's not most people.