Currently, it is impossible to have a properly functioning city (or society for that matter) without some distribution between "knowledge-based" workers and those who work in non-"knowledge-based" fields. Just like you don't want everyone to graduate with a degree in CS, you don't want everyone to abandon necessary jobs because they're "beneath" them. For the forseeable future we're going to need janitors, mechanics, carpenters, etc... (basically most of the occupations that you'd see in a vocational school type setting) and that's a good thing because some people love doing those things. Not everyone wants to spend the majority of their waking life in cube farm under flourescent light.
The criteria that this survey used are probably some of the worst possible criteria for determining any group's "intelligence". You might as well also judge it by the number of cable/satellite channels available per home.