While there are pockets of gentrification in the East Bay, there is much poverty and desperation and the job losses wrought by Covid have aggravated the situation.
Can't speak for the People's Republic of S.F., but here in the People's Republic of NYC, poor people are as law abiding as any other group.
Bike thieves (like most thieves) pretty much choose to be thieves as a way to make a living because they are criminally minded scum and are not necessarily poor.