There is definitely culture clash in this. I think it is probably better to normalize "available" and "unavailable" spans for the knowledge workers who need flow to work effectively. (And I am one.) If my plan was to write a prototype or debug a difficult problem, it doesn't matter if I'm expected to respond to "Hello" or "Hello, <30 word question>", I lose my flow and the job will be delayed. I might even end up permanently distracted on something else. Better would be to connect a pomodoro timer to status that says "Available at <+30m>" when the timer starts. Then I could respond to "hello" and take a quick call and ask the meeting planner to make an agenda.