Keep in mind that when there are no stars in it, it's a fairly inexpensive show to run, with a smallish cast. Even now it's not losing money. It's recouped several times, so even if it does actually start losing money, it can look forward to weeks when it'll earn it back.
The situation is much different for shows that are still struggling to earn back their initial investment. They're dealing with an investment that will never be earned back, and a puddle of red ink that grows bigger with every bad week.
By the way, did DRS earn back its investment?
Behind the fake tinsel of Broadway is real tinsel.