Thanks for posting that full-text as I had not come across it previously. This completely validates my previous comments on this matter that I made from reading snippets of the e-mail. This is a candid business evaluation of data and discussion of how to achieve the desired demographic for season-ticket sales that leads to other cash-generating entities for the franchise. Perhaps a case could be made for being too candid but I read nothing outrageous or shocking.
My guess is he's selling because NOW there is no way the Hawks will recover (because Americans have a problem with reality), and he wants to cash out.