I see what the OP is saying, and at times I've felt the exact same way. That the system was broken to allow such disparity between "builds".
I guess I've mellowed with age a bit. Now I feel that any system that includes rules can be exploited or manipulated because the rules just can't truly address player motivations.
In my career we try to train recruits about the difference between the "letter" of the law and the "spirit" of the law. Even after that training we can't, technically, stop an officer from writing a speeding ticket for 2 MPH over the posted limit. It makes that officer look like a tool to the public and his fellow officers and if it goes to court the judge will pitch it, but it is "technically" unlawful to exceed the posted speed limit; so Officer Tool was following the L(R)AW.
RPGs are like that too. If a player gets off on building a character that exploits the rules in order to "win", then he'll do that with any game he plays. I use to play WH40K, and there were always army builds that were considered "letter Vs. spirit", and they were commonly called "cheesey" or "beardy".
If the group isn't on the same page about the kind of game they want, then a player on either end of that spectrum can suck the fun out of the session for the group. When I started my 4E game, I had a group of people I had never played with before. I quickly learned that one of the players was an optimizer and it eventually caused some heartburn for the group.
This player made a cleric that was devoid of character beyond being dragonborn and having a name. The player set him up as a melee monster and created him as a greataxe wielder. He had almost no healing ability beyond the bare minimum clerics get just for being clerics. I don't have a problem with the build because I'm just trying to cultivate some players and have fun at the game table.
The other players(novices) started to make snide comments about the character when he was more effective in combat than the striker characters, and he never seemed to fail when the rest of the party struggled. Then the cleric player said something at the table that brought a lot of things into perspective for the other players. He said, in an annoyed tone "I can't look through a rule book and not pick the best options.". The other players seemed to feel if he was disparaging them for making "suboptimal" characters.
I personally don't think the thirst for optimization is a death penalty offense, even though it's not my bag, but if the group can't abide it then something has to give.
The group stopped even attempting to work as a team, and as a result they walked into a TPK. The Optimizer then made a halfling rogue that was as optimized as his cleric, but fit more within the new party. He happily rolls his fistfull of dice when he gets a sneak attack(which is often), and the rest of the party gets to shine in their roles.
I don't even worry about the system anymore, I just try to get the PLAYERS to function as a group. If the group doesn't mind adventuring CHEESOR THE CHAINFIGHTER, then I just try to make the adventure fun.