On the extreme right we have the metagamers. They come first because they came first in roleplaying, which evolved out of wargaming, and which routinely recruits people from the worlds of card and board and other tactical games, computer games, and other media which primarily focus on tactics, and offer a means to "win" (or at least keep score) which is paramount. Roleplayers constantly bemoan the abuses of metagamers. Those who admit they're only here to play to win are looked down on, but it's the ones that claim to be roleplaying, but who always bend to fit the tactical advantage, whose characters always somehow end up after the greatest gear or magic items or piles of gold or (most commonly) highest experience level, those are the ones "true roleplayers" really despise. Twinks, minmaxers, power-gamers, they're a stain on the hobby and a perpetual obstacle to those sincerely seeking character exploration and development.
So we've got an easy villain to rail against, and what does that mean? Sure enough, it means people overreacting and going too far the other way. And when they do, criticizing their excesses is an uphill battle, because they're defending their banner of True Roleplaying from the elitist stand of someone opposing an obviously villainous opponent, the Twink. But being opposed to a villain doesn't make you a hero.
Those who elevate character motivations, genre conventions, game feel, etc. to an Ideal, make them an end, not a means, are making almost as serious a mistake as the Twinks. Metagaming has its place; what matters is how it's used, not whether. The fact is, while you're pursuing your character's internal motivations wherever they lead, it still falls upon your shoulders to make sure that somehow, they lead in a direction which:
- is fun for you
- is fun for the other people in the game
- is fun for the GM
- doesn't screw anything up for anyone else
- doesn't make anyone else waste a lot of effort and time unwillingly
- doesn't make your fun come at the expense of others involved in the game
All in all, you have to remember that Not Metagaming is not some sacred trust. It's simply a means to an end. What you're really after is Not Sacrificing Roleplaying In Favor of Metagaming. When metagaming goes against roleplay and fun, eschew it. When it facilitates roleplay and fun, embrace it.