Just pick who you like, I play Captain Falcon, not because I want to prove a point or something, but because I like him and his playstyle. I also main Ike and Snake because I like them and it happens to be so that I have a decent tourney-viable character set with my secondaries, Link, R.O.B., Lucas and DDD, included. Play who you like:
-If it's a low tier, you should consider to main a higher tier also, to prevent higher tiers ****** you.
-If it's a high tier, good for you, but know the matchups and the trouble they can give you and ALSO consider maining a counter-character for your bad matchups.
That's all, it's not a question about whether or not you play for ''fun'' or ''win'', just play the way you like, but know the consequences for doing so, and don't let the stereotype-thinking casuals/competitives influence you.