Well that’s the point. Taylor Swift was not asked to subsidize the MTA. The NJ Transit makes money when ridership increases. They should add trains and increase capacity instead of scalping tickets. Imagine what the scalpers will charge for the train rides.
The more accurate term would be that "they lose less". The farebox recovery ratio for NJT is 40-50%. (From Post 18 by mjustice)
In this case, having to pay overtime and add extra trains will likely cost them far more than the gain, and it's for customers who aren't their regulars. Those regular customers and New Jersey taxpayers will face rate increases to cover the losses.
In addition, for most industries, there's a point where increasing production will cost more than the gain in receipts.
Store foot traffic is a good example. Keeping a store open one hour longer serves more customers but requiring overtime for staff or hiring additional employees to cover that hour could cost far more than the receipts, much less the profit.