I just gotta say I agree with the guy in the video. It's always been the way I look at tier lists in any game. Though, I will always play the character I love the most because
#1. So many patches jumbling up the tier lists
#2. My mains are just characters I love the most. Whether it's the character itself (like Meta Knight) or it's gameplay (like Link), it gives me motivation to keep playing smash. I'm not going to play a character I hate just because it's higher tier like if Wario or Jigglypuff became SSS tier somehow. Besides, it gets me excited to play against someone using a "superior" character and I have to use my skills to beat them in any game. Right now, I don't have a main or secondary that is A rank in the latest tier list (though Fox is a tertiary character for me in SSB4).
#3. I know I'm better than anyone in my area anyways. Not sure how well I'd do in a tournament though.
And a few other minor reasons as well.
I gotta say though, matchups are definitely a thing to look into. I kinda learned how drastic of a change that can be when I was just practicing with Fox in Brawl. Normally all the computers are rather easy so I don't really try that hard, but when I had to fight Sheik, it caught me way off guard how tough she was to fight with fox. I never have problems with Sheik with any other character too. So that was interesting. Made me feel a little better when I saw the matchup chart on ssbwiki say that fox has a -3 handicap against Sheik though.
Do we have any sort of matchup chart for SSB4 yet?