This is also sometimes called a "naked ping"[1]:

  <Bob> Alice: Ping

  <Alice> Bob: Pong?

  <Bob> Alice: Can I talk to you now? I have a question.

    [LONG SILENCE...]

  <Alice> Bob: Sure. (Inside Alice's head: "Sigh, please ask the question, already!")

    [Again, in some cases, this is followed by a LONG SILENCE...]

  <Bob> Alice: A vague question with not much details.

Now, imagine what a test of sanity it becomes if it happens several times throughout the day, week, month.

Note, though: I don't mind "naked pings" myself; they don't bother me much. But I of course appreciate "fully dressed up pings".

[1] https://fedoraproject.org/wiki/No_naked_pings