To be honest, I don't blame you for maining the pitiful character you currently do, as you have to have a very high IQ do understand the mechanics of Yoshimitsu. His moves are extremely subtle and without a solid grasp of the games physics most of the complicated (not for me) combos will fly over a typical players head, just like Yoshimitsu does with his Death Copter landing a devastating unblockable finisher.

Speaking of unblockable finishers, Yoshimitsu has by far the highest amount of unblockable moves of any character. He is not meant to be countered. The best way to play against Yoshimitsu is the lay the controler down and walk out of the room in hopes to not see the carnage that Yoshimitsu will unleash upon your main. Since Yoshimitsu is clearly so far ahead of everyone else he was given a sword to further reduce the amount of time it would take to decimate every opponent.

If I have a good day though, I may hide it, to not further intimidate you (as you are proably allready panicking, knowing that your promotion will soon turn into a demotion). The real reason no one plays Yoshimitsu at a high tournament level is because it would only demonstrate how pathetic every other character truely is.