I think the ridicule comes from the fact that it had the feel of a regurgitated ELI5 explanation that someone had given to him. You can't exactly call it inaccu

I think the ridicule comes from the fact that it had the feel of a regurgitated ELI5 explanation that someone had given to him. You can't exactly call it inaccurate, but it was a bit like hearing "an airplane is like a big metal bird" from the head of the FAA. (A sibling comment points out that calling them "tubes" instead of "pipes" reinforces this garbled-regurgitation impression)