Well, I've read through the entire thread(even the tangents), and I feel I can add something. You want to learn to be more accepting of other playstyles. One poster suggested getting to the heart of why it bugs you, which isn't a bad idea at all, but I'm going to back up the idea of learning to understand the Optimizer mindset. I find that when you find out why people do things, even put yourself in their shoes for a minute, it really helps the empathy.
To that end, I will ruminate a bit about my own playstyle, why I play the way I play, and what I get out of it. Those not interested in such a read can pretty safely skip the rest of my post.
Firstly, I identify as both a Roleplayer, and an Optimizer. I'm kind of a perfectionist about character creation. This will be important, later. I won't put a character into play until I can be proud about him(or her) in all aspects. I won't be satisfied with the RP until I can see my character perfectly in my head. I need to know how they talk, how they walk, how they hold themselves. I need to know how they act and why. Their personal history needs to be compelling, with hooks to lead into the campaign, and I need at least a few good ideas on where they might end up, as a person.
It seems natural to me to be just as exacting when it comes to the mechanics. If I care about the character, why would I let them be poorly represented by their own sheet? The mechanics are the medium by which a character is projected into the game. Just as I would prefer to watch a good movie on the big screen, instead of a crappy 12-inch with a broken color shader, I want the vivid ideas in my head to be well represented in the medium of rules. I want the character to have strong defenses, a decent skill selection, and as much punch as I pack into a power selection. Sometimes I do two, three different stat arrays, weighing the pros and cons of each before settling on one.
But why strive to 'win'? This is a cooperative game! Well, yeah, it is. And I try not to ruin anyone else's fun with my fun. At the same time, you can totally win a cooperative game without having the other players lose. When the whole party overcomes a challenge together, it can be friggin' great! And plunking a 14 in my primary stat doesn't do a hell of a lot to get us there. Also, winning isn't just a final outcome, it's a few dozen little moments each session. When I pick up a d20, I get a little thrill. I move my mini, I start to describe my action, and toss the die. When it comes up in my favor, I get the flush of victory. I go on to describe the action with a twinkle in my eye. When I lift my blade to protect the innocent from the forces of evil, and I roll a 3, it's a letdown. I optimize in pursuit of the flush of victory. The same principle applies in any mechanical area. When an attack is leveled against me, and the Dm asks whether a 19 hits my AC, I want to confidently reply that it does not, not to reluctantly admit that I am taking 9 damage.
Also, Optimization does not have to be only about combat. It's about having a goal, and reaching that goal. I remember one campaign where we ended up having two Barbarians at the table. One was mine, the other belonged to a casual gamer who hadn't had time or inclination to make a very powerful character. Usually, in 4e(the game we were playing), it's not that hard to mix a more and less optimized character in circumstances just like this, but with us both being the same class, any disparity was gonna be obvious. So I took a sharp turn and optimized for maximum distance traveled possible in a single turn. I think I got to about 42 squares. It was still fun to do and talk about, but came up a lot less often(I never actually had a chance to go all out) in game. It took a lot of pressure off the situation.
An odd interaction I've noticed is that sometimes Optimizing helps my Roleplay. It does this by getting me to consider combinations that aren't always obvious and that break away from my normal style. For example, I've been working on a Revenant Fey Hexblade concept recently. Now, I usually don't play undead characters, but the Revenant has the mechanics I like best. It led me to ask myself the question, "But why would a dead guy have made a pact with a Fey Lord?" I won't go into any more detail here, but suffice to say, I found the act of answering the question to break me out of my "type" and I found the answer to the question fascinating. And that wouldn't have happened if I just played him as a suboptimal race.
