Sounds like it is all perceived delays. If they're following a schedule, and are right on time, even though it could go faster... then it would be ahead of schedule, and you'd get bunching.
This reminds me of the stories of the operators at the Morgantown PRT who told me that kids complain endlessly there that "the car just sits there with the door closed after I push the button, and 5 minutes later, THEN the door opens." What they don't realize is that the system is waiting for other passengers who are going to the same desitination... if every car boarded and departed as soon as one passenger boarded, it'd be terribly inefficient and the throughput would plummet.
I know it's not the same technical situation, but it's the same human response - perceived vs. actual/overall capacities, that kinda thing.