The problem I think is not so much a technical/business split, but the fact that the bar to be a 'technical' cofounder is a little higher, where anyone with an idea is an 'idea guy' or a business type. so while there are certainly just as many very bright business guys as there are very bright techies, there's a ton of not very bright people who end up being 'business people' who give the intelligent business people a bad name.
