With today's social media and cable TV, sponsorship is no longer a good return on investment for most companies. Sponsorship back when, was good because it got exposure to thousands that went to the place for something other then advertising. In its time, there was no widespread internet and only three major networks. Now, there is not much that a company can promote in a pavilion that either won't be obsolete within a few months or isn't already well known. I'd hate to be that guy responsible for sponsorship working on a commission basis.
Eventually, Disney will have to realize that if they intend to remain current, they have to invest in it themselves and stop relying on others to pay for their income flow.