CEO pay isn't 'the issue'.
The issue is an absurd concentration of wealth, leading to the non-productive use of capital that denies opportunity to most Americans, that has the power to corrupt our political system and to extract wealth from everyone else, to turn the US into a plutocracy in a cycle of increasing concentration allowing even more concentration.
CEO compensation is just one symptom of the issue that sticks out.
The top 1% have more than doubled their share of income from 10% to 24%. The top 400 individuals have more wealth than the bottom half of America (150 million).
Concentrated ownership is parasitical, draining from America. Distributed ownership is broad prosperity.
As the economy has more than doubled since Reagan took office, every penny after inflation has gone to the top 20%, and that's very concentrated to the top part of 1%.
Higher union wages are indicative of the wealth being more distributed to the public, they increase the share for union and non-union people. Hence, a lack of outrage.
Having a problem copying the chart, but look at this chart for why the outrage:
http://lanekenworthy.net/2010/07/20/the-best-inequality-graph-updated/