Yoda and the Magic 8 ball

Ok on an off topic. I love the Star Wars movies but I can't stand Yoda. He is totally worthless! He is the magic 8-ball of Jedi. Any time he is asked specific question he responds with, "Difficult to see it is", "Hard to tell the future is", "Clouded his destiny is". Why doesn't he just say "Ask again later?" I mean he is really useless. He trained Count Doku...good job on that one. Then he couldn't beat Doku or the Emperor whom only he was supposed to be able to stop. Yeah, I know the Emperor cheated but comeon, he's a bad guy. He gets to do that. He did train Luke and the job he did could be argued either way. He beat Vader but then he throws away his light sabre when the Emperor approaches. You lose points for that one Luke. Yoda must have missed that lesson. Ok it's out of my system now