I think the original post may be on to something here. Not that fighters are bad, they are just an overly broad archetype, that gets most 'mundane' things (at least combat related) lumped in. It can be nice to have mechanically different "mundane" classes that fit the warrior role like Essentials' Knight and Slayer. It need not proliferate into a gazillion narrow subtypes, not if done well. After all, there is a reason that most the splat books have YAW (Yet Another Wizard) syndrome. There is a lot of design space to do cool things in combination with magic system to make new and interesting classes and archetypes. With warrior types, it is usually: yeah, just pick a fighter and these special feats, that's got that covered (unless it involves adding a dash of magical ability). Or, you can go back to 1e where you have classes that were "like a fighter, just better" (i.e. Paladin & Ranger), and the fighter was the consolation prize for not rolling high enough stats.
That being said, I doubt if anything like that will be done with the fighter in D&DN; it would be too controversial.