Second page, near the bottom:
The Stormwind Fallacy, aka the Roleplayer vs Rollplayer Fallacy
Just because one optimizes his characters mechanically does not mean that they cannot also roleplay, and vice versa.

Corollary: Doing one in a game does not preclude, nor infringe upon, the ability to do the other in the same game.

Generalization 1: One is not automatically a worse roleplayer if he optimizes, and vice versa.
Generalization 2: A non-optimized character is not automatically roleplayed better than an optimized one, and vice versa.

(I admit that there are some diehards on both sides -- the RP fanatics who refuse to optimize as if strong characters were the mark of the Devil and the min/max munchkins who couldn't RP their way out of a paper bag without setting it on fire -- though I see these as extreme examples. The vast majority of people are in between, and thus the generalizations hold. The key word is 'automatically')

Proof: These two elements rely on different aspects of a player's gameplay. Optimization factors in to how well one understands the rules and handles synergies to produce a very effective end result. Roleplaying deals with how well a player can act in character and behave as if he was someone else.
A person can act while understanding the rules, and can build something powerful while still handling an effective character. There is nothing in the game -- mechanical or otherwise -- restricting one if you participate in the other.

Claiming that an optimizer cannot roleplay (or is participating in a playstyle that isn't supportive of roleplaying) because he is an optimizer, or vice versa, is committing the Stormwind Fallacy.