Two potential (not absolute) problems:

1. The reader might not know or might not like the particular song.
2. Writers who embed specific songs into a spec may think the songs will create a specific feeling in the reader, but the emotion may stay trapped in the writer’s bubble, even if the reader is familiar with the music. At the spec level, the burden of involving the audience should fall to the story, not the mental soundtrack. Citing a song shouldn’t substitute for creating emotions through character, conflict, dialog, plot, pacing, voice, etc. If the story is already engaging, then mentioning a specific song probably won’t be a liability.