It would seem there are two types of learning going on.

First, if you slowly start culling/killing the bass that bite lures, the population will tend towards bass that won't bite lures. However, since hardly anyone kills bass in California I don't think this factor plays a large part in increased fishing difficulty. Bass are caught, released, spawn, and their offspring are no smarter than the parents.

However, I do believe bass will learn not to bite lures very quickly during their lifetime, and other bass will observe this behavior and stop biting as well.

For example you cast a huddleston across a point with 10 bass sitting on it. One of the bass eats your lure and is caught. The other bass see the commotion but at this point haven't learned anything.

Come back a week later and make the same cast with a huddleston at the same point. The fish which was caught a week earlier will have a strong negative reaction. The other 9 fish see this reaction to the huddleston and make the connection between huddleston and danger.

In this manner over the course of only a year or two you can train all the fish in the lake not to bite huddlestons even though only a small percentage were actually hooked.

I suspect this is what has happened on many lakes. Under certain conditions the fish will overcome their fear and bite anyway, but as long as their are a few fish around to scare the rest, the wide open suicide bites aren't going to happen anymore.

How to fix this problem? Everyone should stop throwing a huddleston for 5 years :) The new bass born every year are a fresh round of unlearned fish, and will stay that way until a huddleston goes past and they see the older fish running for cover.

So... from this point forward... no more huddlestons!