Oh, the arrogance of thinking that the other person doesn't think.
As far as I can tell, the statement in question was simply saying that showing the steps to come to a solution is rare, and also that it helps to teach how to think (how to solve a problem). I guess don't see where the arrogance lies.
It's this part
Most posts of such format I have seen are "we did this and got this", not "we tried this, it failed because of this, then we figured out something else might work and it worked after these modifications".
That doesn't resemble anything remotely related to teaching how to think. You're just logging your trial and error process, which is exactly what each and every single developer goes through on a daily basis.
What exactly do you think other developers do?
Even here, we can imagine that had the author failed to actually make anything faster, they might not have written anything at all. And yet, wouldn't that still have had benefit to people? To see things attempted that didn't work, to understand why those things didn't work? Maybe it wouldn't have been as interesting to as wide an audience, but it's important to see failure. Both as a way of learning from others to not repeat the same efforts, but also because its really easy to fall into the trap of assuming you're incapable if you do fail when everyone around you always seems to be succeeding.
Or perhaps as an analogy, almost everyone creates some art in life, and certainly every artist struggles to create that art. Yet it would be a disservice to only ever present art to learning artists as complete master works and paint by numbers replications. We need to see the "happy little accidents" of Bob Ross, the sketch books of iterations on a design, the piles of failed clay firings. Not because no one experiences these things, but because they are instructive on their own in a way that only seeing success is not.
I had this issue at PeerDB where we'd blog about some dev, when I wrote it'd be a stream of consciousness trying to communicate the mood, frustration, & flailing process. It wouldn't get published, in favor of blogs with clearer product messaging