San Francisco needs an income tax. So many people enjoy the benefits of living in SF but pay little for its upkeep.
CA state income tax rates are up to 7.3% higher than AL's, BUT AL's maximum tax bracket is 5% of any taxable income over $3k. CA's maximum tax bracket is 12.3% of any income over $500k. If you're making $38k (or maybe $48k) or less, you're better off, tax-wise to be in CA. The 6% CA bracket starts at $27,897. [0][1]
[0] http://revenue.alabama.gov/incometax/itfaq01.cfm (Search for "income tax rates")
[1] https://www.ftb.ca.gov/forms/2012_california_tax_rates_and_e... (Search for "tax rate schedules")