If she had started by explaining relativity her post would have been twice the size and she would have lost half the audience. Doesn't it matter to you that people were actually interested in the topic and participative?

And why is a follow up no good? She didn't follow up to fix anything. She followed up to follow up. (And mentioned it by, yes, editing her article).

The problem here is that when explaining things improperly to be "good enough" you have to be very very careful to make it clear what you're doing.

In my opinion, she failed to properly do that and crossed the line between "helpfully simplifying" and "incorrect".

I went through your comments and you mentioned that "in a nutshell" the fact that there's no such thing as a full stop in space is why "this explanation is actually doing a disservice". But that's confusing to me because she clearly stated - relatively to motion - "Those things are true, but we're ignoring that kind of stuff right now."

Can you point out exactly where she crossed the line in your opinion?

The confusion being expressed among commenters here is what I'm basing my assertion off of. Simplification is fine, but I think in this case it pretty clearly set a lot of people down the wrong track.

Some confusion is to be expected. After all, a lot of the concepts are pretty tough to comprehend cleanly.