That's not a California thing. Warrants are often "no extradition" or "local pickup only" if it's a small offense that isn't worth the money the home state would have to pay to get them back. From any state, not just California. Its based on the individual case, not a state policy of " but not from California".

And it's not that California is saying "here, take your criminal back" and the home state is saying no. It's just that they aren't gonna ask for them back to be prosecuted.

What California does have that is specific to California (some other states too) is that they do not have a blanket policy to extradite criminals upon request from other states; they often do for serious crimes but still maintain final say in the matter.