Because Yogi Bear is an old classic cartoon and a title that people will immediately recognize and remember. If a project already has a popular name then it doesn't have to make one on its own while competing with other films.
Oh, yeah? Well sit tight hun, Because your childhood cartoons are going to be continuously stomped on in a very wrong way, sometime in 2011. One little hint..... "SMURFS"
Well, if it's any consolation... the premise of that one is far more original and alot more intriguing than the Yogi one so.....you could try crossing your fingers. Still, im pretty annoyed with all of these half-assed directors and producers re-hashing old cartoons and not even coming up with an original plot...
Oh, don't worry about it too much. I for one, can't remember most of my childhood memories, and the ones I do remember are mostly the bad ones, so they can be choked to death and have their windpipes slowly crunched in two. :3