This is a good idea for a post, however there are way too many mistakes to list. I'll list some of the ones that stick out severely in my mind.
-The Invasion: It was a good idea at one point, considering the previous ECW vs. WWF storyline back in the mid 90s, but they screwed it up big time by bringing in only a few top stars and a whole lot of mid carders. Where was Nash, Hall, Hogan, Flair, Goldberg, Jeff Jarrett, Sabu, The Sandman, Scott Steiner, Bret Hart, Sting? Without the top guys from the two companies the idea seems pointless.
-Kurt Angle: They never should have let him go, or even mad him unhappy because Angle may very well be the greatest wrestler of his generation.
-The NwO: When they introduced the NWO in 2002, it seemed like an awesome idea, they could have easily put NwO over big time and than imagine if they reformed D Generation X at that point? NwO vs. DX would probably be the greatest matchup in years, who the hell WOULDN'T have loved to see that? No, instead they throw em in as outsiders, fire Hall(which I can understand) and have them mire in the midcard for the rest of the year before fizzling out and virtually disappearing. There was so much potential there.
-Ken Shamrock: I'm not 100% sure whether Shamrock left the WWF or his contract ran out, but either way they should have fought hard to keep him in the ring. He's such a unique performer who delivers 100% every time he steps into the ring. His feuds with Owen Hart, The Rock and Steve Blackman were classic. Which is saying a whole lot considering I just mentioned the words Steve Blackman and classic in the same sentence.
-ECW: They started out doing awesome when they brought back ECW, the One Night Stand PPV's were fantastic(who the hell will ever forget Edge and Mick Foley vs. Terry Funk and Tommy Dreamer?)and even had a good couple months of great matchs on Sci Fi, like Big Show vs. Ric Flair when thumbtacks were used, the ladder match over the summer between RVD and Sabu, great stuff. Now though for the last like 5 months its been nothing but crap. ECW is supposed to be extreme, if you don't have hardcore matchs, than what the hell is the point of even bringing it back? Nobody wants to see an ECW brand with 5 minute matchs between Mike Knox and Kevin Thorn, NOBODY. The "New Blood" of performers are absolutely terrible, all of them. If the WWE knew what they were doing they'd let Heyman run the company again(albeit with someone else to watch over funds, Heyman is terrible with those)and have classic death matches with Sabu, RVD, Sandman, Dreamer, etc.
-The Brand Extension: This I saw as one of the lowest points in the history of wrestling. It just was so unnessecary and did nothing but confuse viewers and take away from each brands storylines, also eliminating tons of classic matches that could've taken place. Imagine Shawn Michaels vs. Undertaker? What a huge buyrate that would get. Also, introducing all these new titles was just stupid and did nothing but devalue the original WWF World Heavyweight Championship.
-Donald Trump: Although this is still in progress, I've seen far enough and hope they squash the entire idea, because I don't think theres anyone out there who wants to see A: Trump vs. McMahon, or B: Anything involving Donald Trump ever, ever again. Trump does not belong in wrestling, he's an absolute douchebag moron who if the world was just would be sleeping in an alley.
and finally, one of the absolute worst...
-The Title reigns of John Cena, Rey Mysterio, and JBL: Jesus, enough said right? Cena doesn't even deserve to hold the IC title, let alone the world. He just doesn't deserve it. Rey Mysterio? One of the best of his generation easily, but NOT a heavyweight, so having him hold the World "Heavyweight" championship is pointless. And finally, just the entire character of JBL pisses me off beyond belief, his Bradshaw character was classic and he did not need to change. Him holding the title for as long as he did? Comical.