I'm no expert but I'd say it's a combination of allot of factors, stripers are one of them. I don't care what kind of bounty they offer for stripers they are not going to ever get rid of them unless they drain the lake or they run out of food and eat themselves.
It's a good thing to keep the smaller stripers and they are good eating ( that is if they are not chalked full of Mercury ). and it will help the striper and the LMB populations.
Castaic still has allot of potential though, big deep resevoir that still has a healthy shad population and gets trout plants, I'm sure there are still a few big bass in there.