There are many reasons to be skeptical about the claims the article is making. Correlation vs. causation, and the experiment's relation to executive compensation both seem obvious angles of attack. However, the fact that the study supports what some people would like to believe is not a good reason to doubt any study. Certainly there are some people who would like to believe executive compensation has no impact on how mean you are. Would you be just as skeptical of the reverse finding, based on the notion there are people out there who would like it to be true?

If an experiment's findings are bogus, it is because there is a problem with the methodology or execution. If you want to attack a study, attack it on that basis. If you can't point to a problem with the methodology/execution, your attack is at least as suspicious as that hint of confirmation bias.