The actual design goal is debatable. Thematically what WOTC says in the description is exactly what I would like to see, and in games I play to be honest that is what most of the PC fighters are - generalist fighters. We have an occasional GWM or PAM but they are a distinct minority.
In terms of mechanics, you can build a very flexible fighter RAW if you do things like use a 10 constitution (or 12 absolute max), run a high strength and high dexterity (16 and 14 or vice versa) and good/decent I/W/CH stats. That is a totally doable and playable build and there are subclass features that play into and help that kind of build. In play that kind of fighter is A LOT better than a max damage build IME.
Here on the message boards though most Fighter builds are tricked out narrow "optimized" builds. When it comes to a fighter (and a lessor extent Barbarian) "optimized" really means optimal in one narrowly defined situation if you have the right gear to go with it and bad in just about every other respect. I would like class features that encourage broader builds and the "ribbons" I mentioned mostly do that.