I know the superficial reason why it's called that. It's done in either self-deprecating jest or as an insult. To consistently use the diminutive rather than

I know the superficial reason why it's called that. It's done in either self-deprecating jest or as an insult. To consistently use the diminutive rather than the actual name is to signal to others that you are "in" somehow. That you are "the same". Depending on the manner in which you use it, indicates which group you're looking to belong to. Using these terms and also going full alphabet soup, which happens when people talk shop, isn't for the purpose of disseminating information, but to tell people you are informed. If you want people to understand you, you should be clear and simple.