It's not trivial to have to operate the muting of any indecent words. It's not an operation but nonetheless it's an inconvenience and still a risk. What if the delay device didn't work? And what if some crazy with an anti-WFMU agenda was ready to call and complain to the FCC?
A lot of if's there, granted. Yet, thanks to the US's remedial content purity laws, it just takes one complaint to put any station on the grill.
Having had to deal with this in Orange County CA, a place teeming with old ladies just waiting to complain to the FCC to increase the chance of freeing up an FM slot to a religious station, it was paranoia 16 hours a day for music, 24 hours for spoken content.