As a Sheik player, I actually have a lot of fun playing as Zelda.
I practice with her so I can pull her out a tournaments against bad matchups (like IC) or against newbs.
When you play a low-tier, you really have to learn the ins and outs of a character, good strategy, and rely on superior mindgames. While that's true for any character, since your playing low-tier you are already at an advantage. Its really a good way of practicing your mindgames and technical skills, because you can't make nearly as many mistakes and it helps you play smart.
Technical skill and mindgames transfer well from character to character (not exactly, but the basic skills). If you can kick butt with a low tier through mindgames and good technical skill, you can probably destroy with a higher tier if you apply what you learned.
Best post in this thread. This is almost exactly the way I think as well.
I main Pikachu, and have been for the past 3 years. Why? I like the balance that Pikachu offers. Great recovery, powerful and practical smashes, quick uair spike, good approach game, decent projectile, decent range, horrid grab range, terrible weight... Personally I don't see why Pikachu isn't mid-tier, but I'm not gonna argue that here. Pikachu really fits my playstyle, which is very basic and not technically demanding at all.
Technical skill is an issue with me; I can barely even WD. However, I am a very smart player, which allows me to stay right near the top of Canada's competitive scene. Unfortunately Pika just gets slaughtered by about half of the top/high tiers (Sheik wtf), so in those instances I pick Fox. I've never really dedicated myself to Fox at all, but the perfection of non-char specific technique transfers over. And I do realize that Fox is the most techincally demanding char in the game. Excellent spacing and timing is all that's required for Fox IMO.
In very rare instances I'll pick Peach, but that's dependant on my player matchup (I think I've only played one tourney match with Peach).