While I understand this reaction, I must say that the range of games being shown is pretty impressive. I think it depends on what are the actual limitations (the limitations that a poet accepts can lead to greater creativity, for example).
It's not just about the limitations present in this solution, it's about developing reusable skills. Incidentally teach a standard scripting language to somebody and they have a powerful tool they can reuse outside of this platform.
Gamesalad is probably aimed at turning game ideas into profit in the app store. I don't see a problem with this.