I'm A Banana
Potassium-Rich
For me and my group, we didn't really think about every fighter being the same mechanically, we had different attributes and different NWPS but even that wasn't the big deal, it was actually the CHARACTER that we thought about. Sure, Sasha Quickblade and Valadriel Darkholme were essentially the same character at 5th level, sans magic items, but they were different people and that was all we thought about. In fact, we were so immersed in our characters that we didn't even notice these similarities mechanically until we played 3e. For us game balance wasn't whether the magic user was over shadowing the fighter in encounters but whether or not we got too much treasure or if an encounter might accidentally wipe out a party of 7.
Well, it's not an either/or scenario. With 3e, thinking about the rules is thinking about the character. When Sasha Quickblade takes the Quick Draw feat because her sparkling blade is lightning-fast, that's making her different from Valadriel Darkholme who takes the Blind-Fight feat beacuse of his dark home. They are different people -- and their choices reflect that fact.
Thinking about balance frees up time to think about fun stuff. The 3e rulebooks are focused on rules because rules are what we most need to get balanced and right to be fun. Because if our games are 90% combat and our fighter can't contribute to combat because the wizard can take care of everything, it's not much fun, no matter how many chapters of history I've written about Sasha.
We used to do things like leaping onto chandeliers and other kewl Errol Flynn style theatrics but now it seems like everyone is like "well, you can't do that cause you don't have this *particular series of feats* and it says on page XX you need such and such feat to do this here as well so you can't do that either". I know that isn't what the rules say, penalties to the skill check etc but either the DCs are set so high that the untrained could NEVER accomplish such a tactic or the above arguement ensues.
If your concept of your hero is jumping onto chandeliers, then wouldn't you think that you'd make choices relevant to chandelier-jumping? Jump, balance, tumble, whatnot? And if you don't make those choices, why do you think your character can do that?
3e is a game where you get to do something cool by selecting to do that cool thing over other cool things. If I make a Dex 8 Half-Orc fighter, I'm not saying I can swing on chandeliers or dodge bullets. If he's got a Strength of 18, I'm saying he can break down doors and bend bars and arm wrestle. And lo, he can.
But that's just out of the box. The game constantly encourages you to make the game your own and use your own rules of what's fun. If you want to hand-wave acrobatics (and many of us do), you can. If you don't, you don't have to, and that's worth all the marbles.