NPE and HIMSS confusion

I’m struggling to get my brain around NPE and HIMSS making decisions to leave McCormick Place.

Is it the weather?Chicago does get cold in the winter time.

Is it the business world expressing their disagreement with President Obama? I understand that some disagree with some of his policies. I suppose changing the host city for your tradeshow to a non-Obama city could be one way to flex your economic muscles.

Is it Chicago-style cuisine? Perhaps contemporary diets are incompatible with deep dish pizza and Chicago style ‘dogs – and that would upset expo attendees.

I’m at a loss here, people. Please help me pin down the cause for these two significant tradeshows departing from McCormick Place Convention Center. Thus far, it appears these are totally random occurrences, without any specific cause. Is there any way we can prevent this from happening to the other prominent trade shows held in Chicago?