Awful Coffee, Casual Racism

Maybe it's harmless, maybe it's hipster racism. I've reached a point in my life where this sort of thing irritates me. 

What coffee do Beyonce be drankin'?

All the single lattes

The punchline is clever, built around Beyonce's line, "all the single ladies." But why write the setup in poorly structured English, using "do Beyonce be drankin'" instead of "does Beyonce drink"?

I can't pretend we're in a post-race America and not recognize "do be... drankin'" as being a stereotypical Black sentence structure and phonetization. I hoped this sentence was just referential to a Beyonce-ism. It's not a lyric, so I looked up interviews with Beyonce to see if maybe this is a reference to the way she speaks. It's not. Beyonce doesn't speak this way.

So why write a joke this way? Does the author think the bad grammar adds to the joke and, if so, how and why? I see the use of that appropriated sentence structure, while it may seem funny for the author, as unnecessary, inapprorpriate, and uncool. The El Beit employee, also a white guy like me, didn't see anything racist in what he wrote.