Blame it on the weather. Even when it's not, compared to winters in Detroit, Cleveland, NYC, Minneapolis, Boston and Philly, California was also sunny. The cold, gritty steeliness of the Northeast and Midwest is reflected in the music.
It's also the drugs, heroin vs. LSD.
Neither of these explanations are absolutely valid, but they hint at the differences.
Regarding Lou Reed's musicianship. If Neil Young is considered a great guitarist, then so is Lou Reed.