Agreed. You need founders who can turn their hand to anything, not just their primary skill. I ran a startup back in 2005 with another founder who was primarily focussed on marketing. It was a SaaS that was heavily dependent on data which had to be manually maintained. When he said "I'm not going to sit there wasting hours of my time entering data when I could be selling" it was the beginning of the end. From then on, I couldn't trust him to help out when needed. We folded in 2008.