Mmmm I think you're being overly and ineffectively critical. LA is a gigantic sprawl, digging is complicated by things like, say, the La Brea Tar pits and NIMBY-like stuff, and most of the new rail IS on a grade-seperated medium. San Fernando Valley has dedicated streets for busses, the LAX connector is a serious and immediate part of the plan, and if memory serves the connection to Santa Monica was ultimately finished years ahead of schedule.

Yes, the lack of express lines is a serious issue.

Quite frankly, the LA metro system is admirable failing at a nearly impossible task. It's just too spread out here for the usual set ups to work.

Ironically, part of the spread comes from the original LA transit system. You should look up a map sometime, it's really illuminating.