The turn out

When, as we almost always ask "How was the turn out?" as the first question after an event, what do we mean?

"How well did you do spreading the idea of what you were doing?"

"What did you learn about the people you were trying to reach?"

"How well do you understand what has value for your team?"

"What are you going to do differently next time you do this?"

"Any good stories?"

"What happened?"

"Why?"

Or it is about something else?

What is this turn out?

And why are we so consumed by it?