I was born three years before the last of the L.A streetcars went offline, so if I rode any, I can't remember.
However, just for perspective, when we visit SF, we use public transportation to get just about everywhere. Between BART and SFMUNI, you can get around quite easily. Last time we were there, we took a trolley (
not a cable car) to the Castro and then hopped on a bus to GG Park and another to the Presidio. Buses/streetcars came by about once every ten minutes on the busy routes.
On the other hand, in the OC, where most of the buses operate nearly empty...I once figured out how long it would take me to ride a bus from home to work--7 miles one way. For the time I start in the morning, it would take more than two hours, including a half-hour standing at a bus stop, in the dark during winter. Its a vicious circle; there isn't enough ridership to expand the routes or schedules, and because there aren't enough convenient schedules, nobody wants to ride.
Metrolink is a good option if you're near a station at both ends of your route, and whenever I go urban exploring in DTLA, I take it Because its faster, less aggravating, and cheaper (counting parking) than taking my car. But, unfortunately, Greater L.A. was built around a car culture and riding public transportation, especially a bus, still carries an unfair stigma that the only people who use it can't afford a car. There's an old PE station in Fullerton (now a trendy Scotch bar/restaurant), and I can easily imagine myself taking the car all the way to L.A. back in the day.