Specifically, how the fuck can you have no-knock warrants and castle doctrine in the same system?

So, the cops kick in doors unannounced in the middle of the night, those doors belonging to people who own guns and are permitted to shoot any intruder, and the cops are in turn permitted to then shoot back, and then when these inevitable gunfights arise from this situation, you then charge the surviving homeowners and/or cops?

Why don't we instead charge the legislators for setting such a farce in motion?