It seems to be a common theme, to riff on Grant Morrisons writing because he doesn't completely spell things out for the reader and I have never understood that. He tells you what you need to know to enjoy the story. You don't need to know that Chris Claremont and Dave Cockrum created the Shi'ar Imperial Guard in 1977 to read the New X-men arc where they show up. You don't need to know Well-Spoken Sonic Lightning Flash's origin story before you read Final Crisis #2. You certainly don't need to know that Professor Pyg's name is a reference to "Pygmalion" to enjoy the story of Batman and Robin 1-3. I didn't know and thought it just referenced his pig's mask.