Income disparity, by itself is not a problem, it is a symptom of structural problems in society. As mentioned in that illustrated essay, income disparity would not be a problem if the "American Dream" of making it big was a reality.

Without upward mobility, you essentially have a caste system. The CEO does not work so much harder than a production worker to justify 300x the wage. The CEO may have some personal liablilty attached, but the whole point of coporations is limited liability for shareholders.

I also think Governments are very useful to society. They allow the population to pool their recources for infrastructure (generally a natural monopoly), dispute resolution, and a social safety net. I think giving money to poor people can stimulate the economy more than giving tax cuts to the rich: the rich are very good at aquiring money. The poor will spend it.