Well it is called fishing and not catching for a reason.
I would think that the smaller gamefish that people aren't catching are probably feeding off of the pollution instead of their natural foods, so most people aren't catching them because their baits are too life-like instead of mimicking the garbage. I bet some wacky presentations are probably more successful.
But if they have to blame their lack of success on predators rather than their ability to present a bait that elicits a strike response, then so be it.
Furthermore, if Fish and Game felt that the proportion of flatheads was too high, they would raise the limit, lower the catch size, and promote them as a desirable and available species to fish for.
AZR