Earlier quoted context omitted.
> I believe the author's intent was (or should have been) to describe how THEY wanted to receive communication, not how EVERYONE should I thought that would be too obvious to state.
Most of your post discusses communication in general terms. When you say that it’s unprofessional and rude to begin a Slack message with a greeting before getting to the meat of the issue, there’s no indication at all that you only meant this to apply to Slack messages sent to you personally. At one point you say, “Nobody reads ‘hope you had a great weekend’ and thinks better of the person who wrote it.” Who is going…
I argued why I believe this does not a good way of communication in business or professional-focused environment, because as explained, habitual padding tends to train readers to skim, because they learn that the lines often contain little of substance. For people who value directness (which, in my experience, includes many in serious professional settings) this kind of attitude is not appreciated. That said, it is simply my own rationale for preferring a more direct style of communication.
>Maybe you’d benefit from some of the mindset that leads people to write and appreciate useless greetings.
I come from a culture where elaborate politeness and social niceties are not only common but often expected, and I do practice them in the appropriate contexts. However, when the goal is to build something, solve a problem, or exchange ideas efficiently, I prefer a norm I explained, that is, directness and the substance of the message to take over.