For me, the origin of this sentiment is the culture for certain departments at $LARGE_CORP I used to work for. People would ping me on the internal instant messaging tool to ask for help with things. Sometimes they'd take the nohello approach and just fold everything together in a single message: "Hello, hope you are having a nice day. I'm trying to do X, and I see Y instead of Z. What am I doing wrong?"
And sometimes, they... don't.
"Hello." <wait>
"How are you today?" <wait>
A conversation that could have been done in 30 seconds drags on for many minutes, and the message trickle feeds just fast enough that I can't do anything of any complexity in between the IM app's alert lighting up again. Extracting what they actually want from them feels like pulling teeth. It's a complete waste of their time and utterly disrepectful of mine.
They are there to ask a question. I know they are there to ask a question. They know they are there to ask a question. I'm happy to answer the question, when they finally get around to asking it. Just ask the bloody question, ffs.