A win/loss rate is not an actual rating. I don't know if it affects matchmaking (doesn't seem to), but unless that is the case, there is no reason to care about the number at all. Most highly skilled players seem to be somewhere in the neighborhood of 80%, but their skill with their main and ability to play a variety of characters varies wildly.
You should take some time to honestly consider your attitude, and whether it's how you want to be. Do you really need to think you are so far above everyone else to enjoy the game? The attitude "winning is fun" is what will leave you feeling discouraged, frustrated, and unfulfilled at every turn. Even if you do well in tournaments and challenge the top players, you won't enjoy it. I've fought my share of them, and I can honestly say that without exception, every match I've played with a recognizable name has been among the most boring I have played since the day I picked up 64. It's like fighting a computer, but in the bad way. Exploit, exploit, exploit, wall, wall, wall, chaingrab, chaingrab, chaingrab, etc. You look over at them, and they are completely stone-faced. They look bored, until they eventually lose, at least.
Personally, I can't stand playing that way. I love smash...ALL of smash. The craziness of the stages, the curse/blessing of an opportune item drop, the unfairness/opportunity for badassery of getting double teamed in FFA, and even the occasional 1v1 no items FD. Losing is a part of Smash. A BIG part. You are supposed to lose often by design. You have to be able to laugh when you have a win ripped away from you by some extreme condition. Better yet, you should welcome the extreme condition as a challenge to overcome. When you no longer say "I only lost because of bob-omb/super sonic/mushroomy kingdom", and instead say "I just lost", something like getting two stocked by a fantastic Shiek online won't discourage you. Instead, you'll take it as a challenge to two stock the Shiek right back, and when you do, it will feel great. You'll feel stronger because you overcame a powerful and intimidating opponent. Maybe you were outmatched, but you won anyway because you had guts. Sometimes you will lose more than you win, but you'll come out with a better understanding of the matchups, which is much more valuable than a few more points on your useless record. Let go of your ego. It will hold you back. Losing is your opportunity - it is the blessing of finally finding a worthy opponent who can help you surpass your limitations and challenge yourself to greater heights. Likewise, if you play someone who is far below your level, don't crush them match after match. Use the opportunity to develop some of the characters you are less skilled with. You'll be giving them a better game, and you'll get a better understanding of the cast. It's win-win.