Slash and Burn

Here’s a grammar pet peeve of mine:

Peter Shapiro was bounding around Brooklyn Bowl one recent evening, showing off all that his new music club slash bowling alley would have to offer.

Why is the word “slash” written out? Didn’t we start using “slash” in spoken English as a way of pronouncing the “/” character used in written English? Why not just write “music club/bowling alley?”

What’s with that? I’d seen it written that way once in an alt-weekly before, but this is the New York Times. It must have passed muster with the copy editors. Weird.