i play a high tier because i don't want to play a low tier.
i'm in the "play to win" camp in the sense that i don't want to be limited by my character, but i'm also on the other end of the spectrum in the sense that i don't want to use a "stupid" character and i wouldn't use a character unless i really liked them. (back in early 08 - late 09, i was a fox/falco player, and the only reason i beat anyone was because i had tech skill, so i took drastic measures and quit them altogether as tourney picks and switched to marth so i could force myself to play with stronger fundamentals and less fraudulence)
why i don't want to play a low tier:
-they're mostly boring as **** to play against
-they're frustrating to play as
-i don't want to be limited by my character. i don't choose high tier because of their strengths, but more because they have less hard limitations, and therefore, a much higher skill ceiling. there's a difference between picking a high tier because they can do good things and picking a high tier because they don't have massive flaws. sure, there's probably a lot of undiscovered territory with the low tier characters (e.g. axe pushing pikachu's metagame further than anyone had imagined), but i don't want to take the risk and be that guy. i'd rather use a character i KNOW i can get good with.
-i absolutely despise gimmicks. i respect low tier players that are able to tough out the storm and legitimately fight (and win) against people who know how to fight their character (e.g. axe, wobbles, taj, hugs, etc), but i revile the idea of relying on/hoping for your opponents to simply fight your character the completely wrong way because it's sorta dirty and because it's so unreliable. if people figure out how to exploit your character flaws, what do you do? if fox exploits all of marth's character flaws, then it's a 50/50 (or 60/40, who cares) matchup. if fox exploits all of... zelda's character flaws, then it's at least 70/30. i would rather be able to rely on being able to play an even matchup (using a high tier character) than to toss a coin between capitalizing hard off my opponent's lack of (what should be) common-knowledge and a steep up-hill battle. sure, high tier characters can also win by gimmick because some people are just going to be bad at some matchups (e.g. me beating S2J), but it's much less common, making it less of a factor that you can rely on.