Yeah no. I think that list is almost completely wrong, and definitely for the wrong reasons. And his reasoning and logic is completely off the wall.
The majority of dudes I work with have rolled pallies, druids, and locks, and they all make substantially more than I do, but my class is #2 on the list for income. I'm above average for the country and the state as far as pay goes, but I make less than 89k a year. Granted, I could be an outlier or my co-workers could be outliers, but based on my personal experience and anecdotal evidence provided by others, there really is no correlation between income levels and classes rolled. And hell's bells Jim, lots of people have 3 characters or more.
But going back to anecdotal evidence: my personal experience has been that rogues are always self centered egotistical morons with no grasp on reality and/or numbers and DKs are window lickers that are summed up by the phrase "Why do you even exist?"
Oh... and 98% of the population on Bonechewer needs to be euthanized.