Here's the thing, when I said it was the "hardest" song I'd heard Smith do, what I meant by that was the energy of it and the energy of the beat. It was just a harder energy than he usually does. But when you talk about rap being "hard" people assume you mean the lyrics are violent. Yet when somebody says something about listening to a "hard" rock song, they're talking about the energy of the music, not the lyrics.
The song in the OP came out back in 88. And I remember back then, every hip hop song sounded similar to that. It was mostly East Coast guys, too. But then Straight Outta Compton came out in 88 too. And then rap transformed forever. Nobody wanted to hear corny, positive stuff. They wanted to hear about that thug life. So guys like Will Smith or LL Cool J became obsolete within like 4 or 5 years.
It's interesting how quick that entire rap genre shifted and how major the shift was. It was just as crazy as how much Nirvana shifted the rock scene. And come to think of it....the rap shift and the rock shift both happened right around the same time. Very late 80's - about 94. I never realized that. Hmm.