I dunno man, I kinda take offense to that. :P I argued with Keits about nearly the same thing on WUSRK comments a few months back.
I have to say that the specific type of 'low-tier hero' d3v and Hates mentions really do exist, and you guys are more or less right about them. But their are other players (such as myself) who do the same thing but for different reasons.
Now on this game, obviously I don't play low tier *note the Xianghua avatar :)* unless its my secondary or tertiary, but on other games, like VF, SF, or Marvel, I do. It's not because to make myself feel better when I lose (though I used to do that awhile back), but it's as a personal challenge. Other players *play to win*, but I'd argue that just because you 'win' doesn't necessarily mean you are better than the one you beat. The 'winner' doesn't always necessarily know more about the mechanics of the game, or the matchup, or even about their own character. They might be completely ignorant to all of that and still get the win off of overly generous moves/combos/mechanics. We've ALL felt at times that we lost to someone that we just knew we should have beaten, as well as the frustration and insult behind it.
One thing low tiers have in common in all games is that they almost always have no other choice but to learn and use all available game- and character-centric tools to their advantage. The best example would be 3rd strike Sean. Noone in their right mind would expect a Sean player to win a tournament, because he's so bad (unless you're Kuroda), but concerning only individual matches, even against top-tiers like Chun-li, there is a possibility that you can still win (except on the highest level of play). But you MUST play efficiently; you must parry telegraphed moves, you must know and use your punishers, you must maximize your damage by using the best combos and normals available when the opportunity arises, you must know the max range and priority of your moves, etc etc etc. In this situation, in order to have any chance of winning, you willingly put yourself in a position to force yourself to play smart, and in some cases perfectly efficient/without room for mistakes or mental laxing.
In short, when employed properly 'low-tiering it' is probably the best way to force yourself to become a better player overall. In an almost Zen-like move, you willingly abstain from relying on overpowered/overly generous moves to focus purely on using your own intellegence, creativity, and ingenuity to win. Its analagous to throwing yourself in the hyperbolic time chamber, Goku and the gang/Naruto's Rock Lee wearing the weighted clothing to gain muscle and strength, or Vegeta training rigorously (to the point of nearly killing himself) on that asteroid to reach that next super saijin level of play.
But at the same time, there is a point where you draw a line. With no other better example in mind, in Marvel, playing a Hsien-ko-based team vs. a Phoenix team with all top tier characters can be safely considered impossible in any notable play level.
While this low-tier point is magnified exponentially in Capcom fighters, due to their notoriously bad (and, strangely, gleefully accepted) balance, its not much different in other games. As a Sarah player in VF5, I don't have good guard breaks, a decent 2P, overly generous on-block frame advantages, auto-guard stances, half-life two hit combos, or other cheap gimmicks to rely on -- I have to use my fundamental knowledge and creativity to the fullest extent to be better than you. The same could be said with Mina and Talim players here in SC4. In what sense is simply playing better than your opponent in every possible way to win 'scrub/coward' mentality? How is that NOT, by definition, being 'better' than your opponent? You may 'play-to-win', but I play to be better than you at this game. If you're not trying to be better than your opponent, why are you even playing a competitive game at all? (unless you're already making thousands from tournament winnings)