StreamOfTheSky
Adventurer
To some degree this is true. However, it does ignore a couple of salient issues. Firstly, there is a danger that the System Master starts dictating to the other players what they should take. In a sense, instead of helping, he's actually going further and pretty much writing other people's character's for them.
This can cause a great deal of friction in a group. The System Master can become very frustrated when he sees others taking obviously (in his mind anyway) sub par options and the others can get frustrated because the System Master's priorities are different from the other player's priorities. If you're taking Skill Focus Candlemaking because you want to be a superb candle maker the System Master is possibly going to freak because you're bringing down the party batting average so to speak.
((Arrgh, interruptions, will finish this later.))
It might be a bit frustrating, but if you're a decent human being and respect the very basic fact that It's his character, and he decides what to do with him, you just let it go, and no argument starts.
That's what's great about 3E. If you want to be a professional candlemaker (nay, the best candlemaker!), you can be, and you can stand beside the CoDzilla and the batman wizard. Will you absolutely suck ass in combat compared to the system mastered guys? Of course. But you chose to not worry about combat performance so much, so you can accept that just as the system master can get over the "weakening of the party"* I don't deny you your rights to build your character the way you want, so why do you feel the need to homogenize the rules and lessen how much I can fiddle with my character just to forcibly drag me closer to your purposely chosen power level?
*And I don't buy this. A responsible system master just shrugs at the things beyond his control and works with what he's got. So one guy doesn't want to optimize, maybe more. "Oh well, the DM will just scale the encounter difficulties to fit what our party can handle anyway. Back to figuring out my level 18 feat!" And yes, that means if 4E were the last edition of RPG on earth and I were forced to play it, I would try and make lemonade from the lemons presented to me.
One thing system masters tend to have in common is the desire to crave "challenges." Check out the 3.5 char op boards. There's plenty of threads on taking some race, class, mechanic, etc... that's widely ignored or laughed at as weak, and trying to break the hell out of it. If there were such a candlemaker PC in my party and he was willing to listen to my advice on build so long as it respects his singular focus on candles, I would certainly try and find some way to make that useful in as many situations as possible. Not sure how it could be done, but it'd certainly be fun to mull over!