It removes some of the older fish in the decline of life....one in an otherwise well fed size class, yet is in a less healthy condition is not an efficient hunter...so yes, partially for genetics and predatory tendencies.
I should have added, "underweight in the slightest" once same size class fish over 2 pounds begin looking healthier...
Adding those tendencies, body conditions will help you keep the naturally more aggressive, faster growing fish, and not just aggressively biting a lure because of starvation.
