I know that statement might be debatable, but think about it for a bit. I mean really marinate on that statement. Think of every hip-hop song you've heard on the radio, in the club, on the Internet. Now think of the ones where the artists was really spitting acid on the track. Who comes to mind? Nas? Mos Def? Common? Slaughterhouse (Joell Ortiz, Joe Budden, Crooked I, Royce the 5'9")?
Now think of the song where the lyrics were terrible. Soulja Boy probably comes quickest to mind. (I personally don't think Lil Jon counts as bad lyricism because Lil Jon is more of an American toaster than an American rapper.) Later Lil Wayne might pop up in others' heads depending on what on considers good lyricism. Most of the dance tracks in the club might as well go in to the "bad lyrics" category.
Now, think of the Top 20 songs. Think of the albums that go gold or platinum. Think of the albums that are highly rated. Think of the ones that don't sell.
Lyrics used to mean so much more.