If it stays at this level, it will surpass Breaking Bad.
Hershel got it because the Governor was making a threat. Was Rick going to let the old man die? The Governor wanted to force his hand (and Michonne wouldn't give him the emotional leverage he needed). When it didn't work, two things made him cross the line. First was that he wasn't about to have his bluff called. Second was that Rick did not submit to his demands. Saving face and pure rage equals Herschel with half a neck.
As for Rick being weak, if he had drawn on the Governor he'd have been dead. Or what kind of badass are you guys looking for? What would you have done in the position he was in? His appeal to humanity in the face of being cornered by that maggot took more guts than anything I can think of. If there's someone here with more guts, please enlighten us with how you'd have done it better.
There's more to the character than doppelganging Clint Eastwood. He's not Dirty Harry.