This question is obviously born of hindsight, but the fact that Philip II. of Spain succeeded Charles in the Burgundian territories instead of the new Emperor Ferdinand seems very counter-intuitive to me: Philip was more distant, both in terms of geography and culture (which would factor into the General Estates' discontent leading to the Dutch Revolt) whereas Ferdinand as Emperor would have been in a much better position to control the territories (which were still part of the Empire/Burgundian Circle). Spain, Italy and Milan were already fairly rich, whereas the Austrian Habsburgs constantly had to fight the Imperial Estates for taxes to fund the Turkish Wars and would probably have welcomed the revenue from Antwerp, Bruges etc..

Perhaps (some of) these assumptions are already wrong, my only sources of information as of now are Wiki and Wilson's Thirty Years War (which only notes that Philip received the rich Netherlands, but Ferdinand had the more prestigious title; an explanation I find a bit unsatisfactory).