When I was pioneering, I used to organize some of the weekday morning groups at the Kingdom Hall. If we were to meet at 9:00am, I would arrive before 9:00am and I would often have nobody show up and I would leave at 9:10 or 9:15am at the latest. More than half the time, some pioneers would say that there was "no meeting for field service" at the hall. I would say "Yes, there was. We left at 9:10am" They would always argue with me that they came and the door was locked. I insisted that they must have come after 9:10am because the door was not locked until that time. I never said how "nobody" showed up except me and they never really changed to getting there on time. I was a pretty easy going JW, but if nobody was there, I didn't sit around and hope they would come.
Most pioneers did not want to come to the Hall, but were ridged in counting their time and did not want to stop. Many typically felt that if they came late, the group would be wrapping up, they would be seen to show up, they couldn't get paired with someone they didn't want to work with because people were already paired by the time they showed up. The reason they didn't really change was because most other group organizers would take a long time at the Kingdom Hall. I was always in-and-out. But I had a rotating work schedule and they never knew which day I would be organizing the groups.