Ahh, that word: Judgement. Intelligence and sound judgement are by no means mutually exclusive. Please let no one mistake this post for another paean to the earthy wisdom of the simple-minded. Not that the simple-minded can't also have good judgement, but intellect is no barrier to and often a great facilitator of sound judgement.
But it is not a guarantee of it. Good judgement must be cultivated and one must be able to discern where wisdom that applies in one field may not fit in another, or incompletely, and be able to come to discrete judgements on a given subject. Genius applied to great accomplishment in one field does not necessarily transfer to the ability to give sound advice in other areas, where one has not really cultivated the depth of knowledge to come to an informed judgement.
The old stereotype of the absent minded professor had to come from somewhere, right? This is a good point though - intelligence does not guarantee wisdom, and brilliance in one field does not necessarily translate to others - witness any number of companies run by former sales executives that suddenly lost all notions of direction (my former employer, ParcPlace, being a perfect example of that). Sometimes, skills you learn in one field simply don't apply at all to another. Take something simple - knowing how to swim doesn't mean you know how to be a scuba diver. I've seen it in various board games - there are types of games I'm very good at, and other types of games I'm very bad at.
The same thing goes for intelligence and wisdom. Having intelligence - or skill - in one area does not imply skill or wisdom in another. So let's take this back to the idea of a semi hive mind. I've worked in large groups, and one thing I've noticed is that the collective wisdom goes down as you add people to the group. In a group setting, people will agree to any number of things which they would never agree to individually. We've all seen that in meetings - I have little faith in emergent wisdom happening in a large group setting. In fact, based on the effects of propaganda (both in the political and technical realms) in the past, I'm much more comfortable in predicting emergent nonsense