Like I said before, you cannot understand Shark Tale without knowing of the Toy Story Black Friday reel. The one Katzenberg insisted be "edgy," only to have Woody as an overbearing monster who made horrible jokes to threaten the other toys, and the other toys being just as nasty so they're not even coming out sympathetic. Sharktale was clearly a passive aggressive move by Dreamworks to say "we can do Nemo better by being Edgy" and proving themselves perfectly wrong.
I have to admit, it's not horrible and has some decent moments, but overall a trainwreck. They focused too much on celebrity, and some of them just aren't suited to animation. Will Smith proves that Osmosis Jones was better for him having turned it down, going for Chris Rock instead. And while Angelina Jolie was actually good in both Kung Fu Pandas, she was basically an interchangeable female voice actor here. Only character that was any good was Jack Black's shark who's name escapes me at the moment.
However, I see that film as Dreamwork's early low point, and their films have been getting better ever since. KFP was a major turning point for the studio and HTTYD proved they could do a movie franchise right.