That creates a strong bias for people with lots of time on their hands which I reckon tips the voting bias towards people not actually running a startup.
Karma isn't a function of usefulness to the community, it's a function of time spent on the site, broadly speaking. As such, I suspect that those that have the most experience with startups on average tend to be below the mean in the karma pool. Thus giving those with the most karma an additional boost in shaping the site dynamics would push the site further in the direction of "fans of startups" as opposed to "people working on startups".
Aren't most people here fans of his to some degree? I mean, I don't accept his writing as The Word of Landru, but I thought most people found the site due to his writings and linking to it?