THE FOLKS AT the Pioneer Institute are focusing their attention once again on the MBTA, and their complaint (well, it is actually their recurring complaint) is that the T’s operating budget is spiraling out of control. As evidence of this, Charles Chieppo and Andrew Mikula wrote recently in CommonWealth Beacon: “Since fiscal 2021, system operating costs have risen more steeply every year, including by nearly 15 percent between fiscal 2023 and 2024. The biggest culprit is the bus system.