As much as people like to claim that Diablo 2/LoD had more character customization, no one likes to talk about how their first few characters were totally useless because they put a skill point or stat point in the wrong ability or stat.
That's nothing but hyperbole. There are no characters that become completely useless because of a single skill/stat point.
Whether you believe it or not there are a multitude of builds that are successful in Diablo 3, including melee wizards, ranged barbarians... hell I've even seen people mess around with melee demon hunters to some degree of success.
And what "degree of success" are you using? How far in the game do you have to get to be "sucessful"? You can't make the claim a single skill point gone awry will make a character "totally useless", and then claim that as long as you've got "some degree of success", the character is fine.
Go look at how many viable Hell builds there are for characters in D2, then go look at how many viable Inferno builds there are for characters in D3. You'll find there are more for D2 than D3.