I think you're taking the comment too literally.

I took it to mean something like, "I won't understand an abstruse Ph.D.-level explanation of what happened. I need an explanation geared toward the layperson."

In fact, I think that's closer to the essence of ELI5--as opposed to literally explaining something at the 5 year old level.

I suppose you can quibble about using the initialism, ELI, but only if you're advocating for people who might be unfamiliar with its use. Otherwise, I don't understand your complaint.