I'm from Pittsburgh, PA. I'm the only one out here who listens to Bay music. Some of the shit I play, people love, some of the shit I play, people hate.
1. Gangsta Rap (1996 era Bay Area rap) is no longer popular. The funky beats are cool but the choruses aren't polished for the radio. The topics aren't as relevant to society anymore. Rap music has moved away from the gang banger image.
2. Hyphy - The beats are considered wack by non-thizzing individuals outside of the Bay. Keak makes no sense whatsoever. The Team has great production, but they aren't well known outside of the Bay.
3. Hip Hop (Zion I, Hieroglyphics) - Get their props in backpacking circles, but nowhere else.
A lot of Bay artists are independent. This means that they might make more money off of each album, but they don't have the distribution. They can't advertise like major labels, and they don't control MTV and the Radio.
The hyphy style is a regional style that has to spread, but it didn't spread because its more culturally based than music based. You have to understand the Bay area culture before you understand why people think Hyphy is good. My friends don't ride scrapers and thizz. They prefer music that applies to them.
That's my $.02.