I would argue that Dr. Dre had as much, if not more, influence in the 1990's as Kurt Cobain and Nirvana. I'd have a hard time convincing anyone that anything on The Chronic or Doggystyle matches the musical might of anything on Nevermind or In Utero, or anything on the Unplugged album, for that matter. Three years elapsed between the release of Nevermind and Cobain's death. Over those 3 years, Nirvana redifined Rock & Roll, killed 80's big-hair bands, and invented the "grunge" consciousness. They sold millions of records and achieved international notoriety. Grunge, as a movement, was short lived. As it became more popular, it quickly transformed into a parody of itself. Towards the end of the 1990's, grunge was obscured by the popularity of rap-infused metal, the new incarnation of pop groups, and, largely, by hip-hop. Hip-hop music outpaced the growth of grunge rock and never looked back. The godfather of 1990's hip hop is Dr. Dre.
Dre invented the "gangsta rap" lexicon as a member of N.W.A. and introduced it to the mainstream, especially to suburban whites, with the release of 1992's The Chronic. Its questionable language became commonplace on the radio, television, and, most importantly, in the schoolyard. A generation of consumers grew up using terms like "bitch" and "ho" and "chronic" and "biatch." Whether you think this language is a detriment to society or not, you can not deny the saturation it reached in the 90's. The ground Dr. Dre broke, lyrically, in The Chronic, as well as with Doggystyle (as producer), became a blueprint for future rappers. Taunting enemies, celebrating excess, "repping" your hometown, and overt sexuality was the formula invented on The Chronic and reinforced by Doggystyle. In 1999, Dr. Dre released an album that would prove to be the full realization of what he had done 7 years earlier. 2001, the album, cemented Dr. Dre's reputation as one of the finest producers in popular music.
Kurt Cobain was an icon. A generation of disaffected youth were thirsty for representation, and they found it in the downtrodden and humble front-man of the stripped-down rock band from the pacific northwest. The significance of his suicide can not be underscored when considering Nirvana's legacy. There is a tendency to judge the band by a trajectory based on what they accomplished in the 3 years between the release of Nevermind and the day Kurt Cobain took his life (which was quite a lot). Culturally, much of what was considered "grunge" faded away once Nirvana no longer released albums. The guitars got lower and louder, the singing became yelling, and once again, image become important again and Rock Stars emerged (Kid Rock, Limp Bizkit, Blink 182, etc.)
In an industry that moves in cycles and waves, Dr. Dre never seemed to fade away. The movement he created became much more than that. Hip-hop grew and multiplied and took many different shapes. In a similar fashion, Rock & Roll metamorphosed after the death of "grunge." What distinguishes Compton from Seattle is that the "grunge" movement was a musical and cultural gold rush--eventually, the rivers and creeks dried up and fans were left wanting. They moved on, got tattooed and pierced, and started listening to Linkin Park. And what happened to hip-hop? The rappers became movie stars, publishers, clothing designers, and entrepreneurs. Rappers became the mavens of pop culture. Even seen an episode of Cribs?