there is a trend recently in game design to make the gameplay perfectly balanced, every even the smallest addition that *might* ruin the whole equilibrium is dreaded like nothing else. this leads to extremities like in Day of Defeat: Source where maps are more or less symetrical and the opossing teams have exactly the same weapons.
Dumbing down, I'm sure you all have heard of this and can agree that is not the way to go, nor is it the intention of NS2 developers
I also see the reason behind making games balanced - players these days tend to quickly work out the game mechanisms and come up with the most efficient gameplay style, exploiting every map irregularity, thus intimidating new players and dominating the battlefield. Giving every player the same chances is obviously the solution to this, but it fnally ends up with symetricallity. And even then, the smallest difference in time makes a certain game tactic the best and repeated to death.
I offer another approach to consider however: randomness - glorifying not only personal skill but teamwork, randomness (for example weapon recoil) makes single players less confident but it also has minor affect on the group of players. it also applies to the map design, more interactive elements (completely taken out by Valve in their MP games) aafecting the game flow, indirect ways to fight, less predictability often updates - put one strategy in favor this time, force another strategy next time etc. - constant balance-shifting small updates, can be weapons udates, can be game logic updates, but never let players get used to a given elaborated strategy making the gameplay stale
what this gives us? freedom to implement more features! for example istead of 4 solicitously configured and balanced weapons we can have 15 to choose from, after 3 weeks good players make 3 of that better than the others, and a week after an update comes, rebalancing the whole set. personal skills wont be lost - players will just have to put it again to use instead of blindly practising one and only strategy