Gadget and Underdog have the same problem. They have the barest shred of the concept, but forgot absolutely everything that made the shows special in the first place. I highly suspect they had generic scripts for other projects and slapped the franchise names on them because they were about to lose the license.
Dragonball Evolution, and I SWEAR this is true... that was slapped together because Fox was just about to have the license expire (they bought it 2000 or so at the height of the show's American popularity) and they didn't want the same thing to happen with Watchmen. And we all remember that, but in case we don't... Fox had the license to make a Watchmen movie that never happened in the 90's, and when Warner Bros was working on it, they sued and lost because someone else was going to make the movie they didn't when they somehow had a license that didn't expire, despite them not doing anything with it. So, out of fears that someone else would get the license to make a DB movie, they threw a terrible one together last minute. But hey, at least we got Dragonball Kai out of it.
Bewitched is a very interesting case. I'd never call it a stupid movie. In fact, quite the opposite. They did something clever and original with it... so clever and original that it stunk. Instead of a blatant remake, they made the movie about making the remake. Clever, yes... but all together too smart for its own good. Not an elitist smart, but they cloyingly cute smart of some overly gifted little kid that can spell complicated words that NO ONE uses. The reaction of having to make an "Oh, isn't that adorable" face or comment, when you're really thinking, "get this overly precocious brat the heck away from me before I break something." Though I applaud Steve Carell's cameo as Uncle Arthur.