I think there are two points here.
The first is the watering down of hip-hop as it becomes mainstream. Euron Greyjoy's already pointed out the difference between hip-hop acts of a previous generation and the current crop but likewise if one delves below the "hot 40" or whatever the charts are called one can find a selection of excellent "underground" rappers, MC's, producers etc putting out a lot of quality work, much of which is a lot more self-aware and intelligent than the stuff in the charts. That's not to say that there isn't awful stuff on the underground hip-hop scene... there is, frequently just as bad as the mainstream acts people decry but with a lower budget.
But hip-hop is far from alone in that.
You can take basically any genre that's made it into the charts and see how the current chart darlings generally produce lesser music then either their forefathers or the more underground scene. Punk with the pop-punk craze of the late 90's/early 2000's, post-hardcore with the rise of emo, metal with the rise of nu-metal and the screamo variations, the difference between the pounding techno one would hear if they made it through the queue into Berghain
(something everyone should do once in their life) and the sort of cheesy techno that hits the charts, dubstep fans having to listen to Taylor Swift incorporate a few elements into her songs. Hell, I'm sure somewhere out there there's some country and western fans bemoaning how poppy and commercial all these new singers sound compared to the good ol' days.
As a general rule the mass-market version of a genre is going to be toned down... musically, lyrically and thematically. To use hip-hop as an example it's far less controversial to rap about making a lot of money and having a lot of sex with a soft beat playing below
then it is to "fuck tha police
" over a pretty aggressive backing beat. To take punk it's a lot safer to have a happy poppy song about a failed relationship sung by some nice looking clean cut young men
than an angry, spite-filled anthem about the way the rich seem immune to the law sung by a scary lookin' fellow
. That's simply the way of the world.
But one thing about hip-hop is seemingly unique.
The way it's associated with black (and in particular African American) culture.
Other genres should
arguably be associated with a skin colour as well... rock is largely the domain of the white man, as is punk. Some even are... country and western is largely associated with white people as well. But none of those genres have quite the same connection to race that hip-hop seems to. Country and Western may be associated with white people but it's generally associated with white people from the South of the US... there is no such geographic restriction when it comes to hip-hop. Sure, there's east-coast vs west-coast vs dirty-south and all that but they're all seen as hip-hop and hip-hop is seen as black man's music in the way that other genres aren't.
Pretty much wherever one is in the West it seems to be an unspoken assumption that any black person... regardless of background, appearance or any other factor... likes hip-hop. There's no such assumption for a white person. There may be one based on dress sense or location but simply from being white? Not so much.
And that's rather strange to me.