A recent release from the U.S. Census Bureau's American Community Survey listed the LA Metro region #4 in terms of the number of workers using transit, but the percentage of workers using transit LA is still lagging behind at 6.2%. I think there may be several reasons for the lack of more transit riders, but here's a few:
1. Employers are more willing to subsidize parking rather than transit. Until parking becomes a scarcity it is a difficult sell. Metro has already put in place reduced transit fares for employers through its B-Tap program. Unfortunately, Metrolink's sizable expense results in employer reimbursements' accounting for a very small portion of the cost. In other cities such as SF, DC and NY the cost of a monthly parking spot can equal rent on a small studio.
2. Many of public transit riders in LA are not workers, but rather students, elderly and of course those people who don't ride i.e. the unemployed. Not that other Metropolitan areas don't have the same types of riders, but I think LA has a disproportionate amount of non-working riders. I would be interested to see how LA matches up against other areas when all transit riders are considered.
3. LA has several areas where the majority of workers are headed. Traveling to DTLA via transit is very doable, but other city centers: Century City, Long Beach, Santa Monica, Westwood, Burbank, etc. are so spread apart that having reliable, frequent trips for workers is difficult.
The reasons I ride transit have a lot to do with the fact that my transit is subsidized by my employer; I work in DTLA at a transit hub, i.e. Union Station; and I learned how to ride transit from my time at USC where parking costs over $300/semester (parking scarcity). Take away one of those and I might be with the other 93.8% of workers in the LA Metro area- stuck in traffic, in a car by myself, listening to NPR and cursing.