Do you really want to know why rapgenius needs IPO money or are you just using it as a rhetorical vessel to justify use of such inflamatory lexis as "retarded" and "classic"?
I have no hopes on influencing your opinion but want to provide my version of the explanation. Surely it is only an opinion, I have no authority on the subject.
Rapgenius needs to IPO to massively scale in text annotation business providing context and meaning to texts that are far away from rap. Immense value can be gained if RapGenius or NewsGenius will provide a platform to annonate, verify and explain complicated news articles, scientific studies, techical documentation, anything that requires metadata for better understanding. This feat was tried by many and all of them failed, including Google, remember Sidewiki?
Rapgenius has a leg to stand on -- working annotation platform. If they are able to branch into other areas that are more appealing to mass market, the possibilities of growth are immense.