The author of the parent explains their view well I think (not directed at statistics students). But I would like to make the more general complaint that this attitude seems pervasive in maths. People often fail to include enough detail in their derivations of proofs or their explanations of things and the students are left confused and unsure because they don't see how they got from step 3 to step 4.
I wholeheartedly agree with you, in my case I was typing my comment on my phone while waiting on the train. I wanted to get into as many details as possible but not having access to easily typed math notation made my task harder.
