I think the problem is more general and it's not the culture. It's just much easier to find arguments for how the idea could fail rather than ones supporting it or proving it might work.
I once built an online dish ordering website with interface similar to digg and reddit. It showed dishes in your area sorted by the number of times they have been ordered online. I still host a short video demo of the site: http://video.eatlista.pl/ (it's in Polish language, but still, could be inspiring for someone).
Anyway I ditched the idea after talking to restaurant owners, they were mostly older people, having hard time grasping the concept of the site (and even the Internet itself) and I didn't enjoy the idea of educating them.
The most fundamental problem with natural language search engines is that the "natural language" part is more a limitation than a feature to me. Natural language is meant for people to communicate with other people and not with computers. I believe that a well designed keyword/tag based search combined with factual auto suggestions extracted from formal/semantic sources (similar to wikipedia) could be far more efficient for people to use and computers to run.