That's the biggest problem.
That's another one.
Actually, it's not a problem that fans want this.
The problem is, rappers who normally represented the original hip hop style, felt the need to capitalize on what's hot, instead of staying true to their self. In the process, they don't get the same response as somebody like Rick Ross would get but alienate their original fanbase, who are always under the impression that when a rapper makes a commercial/party record, he sucks.
Rappers still rap about the struggle, it's still a market for that. But in this day and time, a record like Grove St. Party will receive more airplay than a record like Express Yourself would today and thats because it's more marketable.
The big problem is fans are too one dimensional. Guys like Nas get all the respect in the world but if he was to try something new and start collaborating with guys like Waka, Future and 2 Chainz, fans will call him a sell out and completely shit on him because they are not open to change. Record labels don't make money off artists like Dead Prez or Talib Kweli because the fanbase now, isn't the same fanbase of 20 years ago. Honestly, your average music listener isn't as intelligent to listen to artists like that and completely understand it. Rappers now have to dumb down lyrics in order to remain relevant and make money these days. Thats why 2 Chainz has one of the top albums of the summer and Waka Flocka is in high demand, while guys like Talib Kweli, Canibus or Ras Kass won't be as successful and labels won't be as quick to sign them, they lack the crossover ability.
It's all about money but there is no problem with hip hop, as there is something for everybody. People allow themselves to partake in those party records just to complain, it's all a choice. Times are different, more middle class teenagers are hip hop fans and take a liking to guys like Drake or Meek Mill because it's simple rhymes and sounds good. Not everybody can listen to an typical song about the struggle and really feel it, especially if they have no idea what the struggle really is. And even with that, the bling bling rap and the trap music, it's all becoming redundant.