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 to read that and think that “nobody” only applies to you?
If you really meant this to describe how you want to receive communication, not how everyone should, well, this is an example of catastrophically bad communication. Maybe you’d benefit from some of the mindset that leads people to write and appreciate useless greetings.
> 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 to read that and think that “nobody” only applies to you?
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.
As you said yourself, this is very culture dependent.
In my culture, elaborate politeness is NOT expected, and when I first started working with foreigners I had some funnily awkward (awkwardly funny) social interactions where they greeted me with customary "How are you? How was your day" and I started politely but awkwardly going over my day thinking "this is not your damn business".
My point being, if you work in a culture that expects some behaviour, it is necessary to follow it. Breaking the protocol (even by omission) is a signal in itself, and if the signal is understood as "I don't like you" or "I am rude" or "I am better than you" then it's counterproductive. Especially important if you're not close with the person communicating with, so misunderstandings are likely.
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 to read that and think that “nobody” only applies to you?
If you really meant this to describe how you want to receive communication, not how everyone should, well, this is an example of catastrophically bad communication. Maybe you’d benefit from some of the mindset that leads people to write and appreciate useless greetings.