The detail it deserves doesn't fit in an HN comment. But I'll drop some observations here. You really need to experience it to get it though. Body language and so many other nuances all come into play in any communication style.

I'll suggest that it's the interruption culture itself that is motivating the tendency for monologues.

When an executive regularly says "John please let Mary finish, I wanted to hear the rest of her thoughts" it sends at least two signals:

1. The obvious that interrupting is not welcome here. 2. The less obvious but easy enough to figure out that listening is valued. The vast majority of folks are smart enough to figure out that a monologue is just as unwelcome as interruptions in a culture where listening is valued.

At the the end of the day what everyone wants is a dialog. In a non-interupting culture folks tend to pass the baton far quicker which takes the place that interruptions used to serve. Once people understand that they will get uninterrupted time to speak, they relax and aren't so desperate to get everything out all at once before someone interrupts and shuts them down.

Imagine a manager who tells you that she can give you 30m max, no interruptions. That's a lot of trust and responsibility they've put on you. You pretty quickly figure out how to make effective use of that time, and it's for sure not a monologue.

And it's also manageable over a series of meetings. It's easy enough for a manager to start a meeting with "Kevin, please hold off your thoughts until the end of the meeting because we heard mostly from you last meeting".

People catch on very quickly if it's coming from the top. Which it almost always has to.