The problem is, they justify the high salaries as what it takes to secure the top talent. Experienced CEOs that will guide their businesses to success are in high demand, so the market for them dictates high pay to attract them. If conscientious companies pay their execs less for a fairer distribution of wealth, they’ll have trouble attracting the best people at the top. Those people will simply go to a competitor who doesn’t mind paying 1000 times their average wage.
This only really works if all corporations decide to do it, and we know that’s never going to happen.
I think we’re kidding ourselves if we think most consumer care enough about this to make dramatic changes in their purchasing habits based on how much the company’s CEO is paid. A handful of people will. Billions won’t. And that’s unlikely to create any significant change.