Light rail in the US in the past 50 years has objectively been an over priced under utilized boondoggle. It's entirely believable buses may well have been the far better option for crossing the golden gate, even if a guy who works for the light rail system today doesn't think so.
Having ridden both BART and the AC transit bus system across the bay from SF to the East Bay countless times, I'll take the bus over BART every time. The bus system is better, cheaper, cleaner, safer feeling, and faster.
Bus systems are cheaper and more flexible in the face of population density changes and land use changes than light rail. You don't need a conspiracy to have concluded bus systems are a better transit solution than light rail. Rational economic analysis can get you to buses just as easily (though you do have to fight off the lobbying campaigns by the large construction firms that want to tap the insane stream of public funds available when building a light rail system).