Big Daddy Kane is not a secret. However, the people who are interested are not necessarily sincere and you got people who are Jay Z fans just because Jay Z is popular at the moment. They can't explain to you how his style is or what he does lyrically or metaphorically. And certainly, the criteria is never a matter of written law, more or less unspoken consensus that's constantly being contested and disagreed over. The latter might argue that Dre and Cube couldn't hold a candle, lyrically, to cats from their hoods like De La Soul, Mobb Deep or Wu Tang.
ALL artists do it from now and then, but in varying degrees.
Nas seems to me to be far more fickle, which is not to say that his talent isn't there, but I don't anticipate a Nas single like I used to. I mean positive more in terms of progressive - on Cube's first three solo joints, he wasn't blindly celebrating the life of a gangsta but was also trying to channel that rage and intensity into a larger sense of social change and vision. Now though, Cube wants to be a player instead of the commissioner, not longer interested in changing the game, but in excelling at it.