He's referring to high crime rates. Parts of Oakland does have extremely high crime rates, much higher than even SF's notably elevated violent crime rates.
Many Oaklanders would point out that not all of the city suffers from extreme violent crime, but it would also seem that the areas convenient to a SF commute generally tend to be worse, and the good areas aren't that cheap.
It's not just the violent crime rate, either -- it's that the police, as a matter of policy, don't give a crap about anything that doesn't involve blood in the street. If you call the police after your home or car are burglarized, they will basically tell you to stop wasting their time.
If you're not a thug, all evidence (or at least many anecdotes) suggests that Oakland doesn't want you.
I would assume it's the violent crime rate that causes the police to shrug off lesser crimes. I doubt the police do it because they only want gang members in the city — which seems like an extremely silly thing to think.
They mean to get stabbed by a knife, a common misconception about the east bay. Yes there's violence, but theres also beauty, you just need to know where to go and where not to go (san francisco is the same).
#3 crime rate in the US isn't a misconception. Anecdotally, of 6 people I know who have moved to (relatively nice) areas of Oakland, 6 have had their cars broken into or robbed at gunpoint. 4 are currently looking to move elsewhere.
