The ZZTopping of America is finally receding. I think it had a lot to do with all the guys going to Iraq and Afghanistan in the wars and seeing how real men live. None of this post-Victorian sissyfied babyfacing for these menfolk.
My thought on Riley's beard is that it covered a somewhat weak chin. This makes him seem more menacing. "I have a weak chin and i run weird but I also mash and make great plays!"