The purpose laid out at the beginning of the video was the ease of developing UI code. But in reality, the author does almost no UI development. He sets up projects, and then in every case where a UI could be auto generated, uses it verbatim.
Forgiving the overwhelming simplicity of the sample project, the video gives little insight on how difficult it is to modify and fine tune interfaces, with the notable exception of pointing out if they work in "html editors". I do not know a single serious developer who would trust his html to a wysiwyg html editor.
J2EE sucks.
Rails, Django, WebGears, and Zope are pretty nice.
The problem with this demo is that both examples (hello world, and a time tracking app) are very simple examples. While it's very easy to do simple things in Rails (can't speak for the others), it's still hard to do moderately to very complex things. There's no magic bullet.
That said, Rails, etc to make things more fun and take some of the grunt work out.
Forgiving the overwhelming simplicity of the sample project, the video gives little insight on how difficult it is to modify and fine tune interfaces, with the notable exception of pointing out if they work in "html editors". I do not know a single serious developer who would trust his html to a wysiwyg html editor.