Man, this show gets such a bad rep. Everyone loves to bash all over Stitch's Great Escape. That's pretty obvious. Personally, I do enjoy the show. It's not my favorite, but I can appreciate it, and I'll try to explain why.
First off, Stitch is one of the best animatronics anywhere. A beautiful range of motion, and a great likeness. Sometimes character figures don't translate very well into the real world, but that's not the case here. Secondly, look at what options they had to work with. Now look, I'll admit that I would've liked to see him get a new ride, rather than just imported into an old one. However, look at the fact that Alien Encounter (the previous show) had terrible numbers, scared children, and seemed a bit out of place amongst the other rides like Buzz Lightyear's Space Ranger Spin and Space Mountain.
So here're your options: re-theme the show with the most popular new character in years, thereby saving time and money on new construction and clearing out an unpopular show; or figure out where to put a new show building, spend money and time on new construction, and in the end still have an existing show that no one likes.
Hindsight being 20/20, everyone blasts them for making the decision that they made. But you know what? If the show were mega popular, everyone'd be going on and on about how smart they were, killing two birds with one stone.
(And before anyone jumps on me for bringing up money and time in regards to Imagineering, please remember that Disney is, at the end of the day, a business. If they spent $100 million dollars on every new ride, they'd go bankrupt.)