Ah yes, Cali and AA, an interesting study of how not to operate, and expect to survive.
Using automation, the crew decides to alter the approach sequence at the last minute, inserts a waypoint which they think is correct (but the database proves 'em wrong), ignores very basic raw data information, and descends into a hill, with go-around thrust selected/speed brakes extended.
Absolutely no planning or forethought whatsoever.
Autopilot use is fine, and on more modern types is highly recommended for ease of operation, but you gotta remember...garbage in, garbage out with the FMS/FMC.
Far too many 'new generation' guys expect the machine to never fail/always be correct.
Sadly, is does fail...and you have to pay attention.