Yes, it can be. The reason it's built in to the mic is to protect the mic's output transformer from distorting when recording louder sounds. Most newer/cheaper designs of condenser mic use solid state outputs (unless they're deliberately apeing a classic design) which typically are less easily saturated by loud bass sounds.

I'd guess NPR's view is along the lines that, well, the filter's already there, and we like the way it sounds, so we keep using it.