The point of a demo isn't to be user friendly (though that is of course preferable), it is to allow people a chance to check out the game so they can decide if they wish to buy it or not. Most of the game demos I've tried I knew fairly quickly whether the game looked promising, or not. A few I kept playing to see if I could get used to some quirk or if gameplay would get better, but usually my first impressions carried through to the end of the demo.
The demo I mentioned above that expired after 30 days was for the game Psychonauts. Playing it on a laptop I hit a section I could not get past, which required some timed, coordinated jumping and attacking. I assumed this would be much easier with a gamepad than a trackpad and arrow keys (it was, but still annoying), so made my purchase decision based on the gameplay up to that point.
That said, I'm not sure how lack of saves is suppose to be a net benefit, I just don't think it is a huge problem.
A 50+ hour game that has no saves? That should ring untrue to anyone with a little common sense hearing that.
The upcoming patch should be released soon. While it wasn't specifically stated that it would address the hanging cutscene problem some people have experiences, there are several suggestions in the forum for fixes that have helped in a some cases. Saying this bug 'has existed for months' is a little melodramatic since the game has only been out a couple months or less in most regions.
