If you've been reading my blog for a while, a recurring metaphor you'll see that I come back to over and over again is that of Hunters vs. Farmers. 'Hunters' in this case are the innovators and entrepreneurs that start a company and create the vision. 'Farmers', by contrast, are the individuals who go execute on that vision and, more often than not, scale the initial vision far beyond the Hunters who created it.
Both are necessary, and there needs to be a balance of the two of them in any organization in order for it to succeed. When I see companies that are too heavy in either Hunters or Farmers, it's often a source of trouble as there is either a deficiency of focus and execution (too little Farming), or a deficiency of vision (too little Hunting).
Don't get me wrong, everyone should be executing relentlessly in a startup, not just a chosen few, however both roles require dedicated attention and finesse. I have seen more than a few startups that were created by Farmers who had a small spark of vision, only to have them obsess on the execution to the exclusion of everything else. This is often fatal, as 'vision and strategy creation' is not a discrete event that happens at an annual 'Strategic Offsite', then put on a shelf next to all the other folders of years past. It is a constantly evolving and adaptive strategy that best reflects the continually-changing world and marketplace we live in.