Because Ops and A&D are two different departments. A&D develops idealistically. Scenes are designed with a passing sense of how it takes to complete and reset. Their concern is the show, and whether it takes 3 seconds or 30 are secondary to the story they want to tell.
Ops are the ones in the mud trying to keep lines down. All they care said the time it takes. From their perspective, it's not one person waiting 10 seconds to watch a waiting- it's the hundreds of people behind them. Thus, the rush.