The alt-text panel hints at this, but the problem with making up a fake group everyone can hate is that racists and bigots will stretch the definition to include whatever they want.
We've seen it with "antisemitism" being redefined to include any criticism of Israel, and before that "pedophilia" being redefined to include drag queens and parents supporting their trans children. For that reason, hatred like this should not be encouraged, even if it's imaginary.
My interpretation of it was that it was satire and not proposing the creation of a fake group. In short, I perceived it as being in agreement with everything you said.
You're right of course about this being satire. My fear though is that things like this can fall out of the author's control very quickly, much like Pepe the Frog, and I really don't want gratch to be a catchall dog whistle.
Do you have any examples of this? Because my experience is the opposite. It's the perception that your group is normal, the "default", and tearing down all of these other groups using phrases exactly like the ones in the comic.