It... Is... A... LAUNCH.
We should be so fortunate that there are even kiosks in the first place. It's hard to put together a demo. Time must be taken to code and build a disc that ONLY plays 1 level or so. So if the kiosks come out 1 month before launch (as they did with 360), and it took 1 month to build the demo disc (which I'm probably being generous on), then the demos on the kiosks are at minimum 2 months younger than their final builds! And I'm SURE developers aren't happy about drawing resources off a project that they will probably be working overtime on until the last possible second. So the demo discs are old builds, that aren't getting full publishing attention... surprise, they have bugs. This is not dumb... it's what they had to work with. I don't believe Xbox or PS2 had any kiosks out until after the holiday rush anyways.
Chill. Most optimizations take place in the last 2 months before launch.