Although the Superstars Model provides a theoreticall framework to study inequality, I think that the book is biased towards it. Lectures on microeconomics could be significantly improved by extending section 5.2. Risk seeking is indeed a major factor that contributes to inequality. To see this in an experiment, look at the paper that is referenced below, where the inequality of initial wealth and the inequality of rewards are determinant factors in the decision making process of risk taking. As the Casablanca example shows, the inequality of rewards was the powerful driver of taking the gamble in the casino. If, in adittion, evidence and empirical analysis towards this argument is provided, I would think that it would contribute to a more complete and broader view of inequality.
Bibliography: _Hopkings, Ed.__emphasized text_Inequality and Risk-Taking Behaviour.Available at: http://homepages.econ.ed.ac.uk/~hopkinse/ineq.pdf