Why? Why not? If you need to move 1000 people to a given destination over an hour, and you run every 15 mins, and 1000 drops to 800, then approx every 20 mins will do.
But that's not drop in service (as it will be spun). That's just a common sense response to the needs of the market.
The problem is, any elected official who champions such common sense won't get elected / re-elected. Simply because it will be sold to the public as a drop in service. This why public programs always grow and too rarely never re-adjust (smaller) when appropriate.
Note: The article did __not__ say why ridership is down. It mentioned the reliability issue but doesn't name it as the sole reason. For all we know more people are walking because the need the exercise. Or perhaps those at the bottom of the economic ladder can't afford to ride.
Obviously, the former is good news. Healthcare is expensive. Obesity is a real issue.
Obviously, the latter is bad news. And few elected officials what to be the ones to say they haven't been doing what they said they were doing.
Or perhaps tourism is down? Which again, is not a feather in any politician's cap.
Anecdotally, I live in Central NJ. To take the train to NYC I have to pay approx $10 to park. That makes the round trip approx $40. In my mind, at $40 p/p p/trip, that's coming up on $50, opposed to a (psychological) shade over $25.
The article makes no mention of possible external factors.