Can someone please explain...

Can someone please explain to me WHY american tv executives force the scheduling of playoff hockey games (traditionally night games... hello? Hockey Night in Canada?) into mid morning/early afternoon time slots on the weekend, but insist on taking baseball and football playoffs (traditionally day games) and forcing them into prime time or late night time slots?

Is there a labotomy needed to apply for these positions? Or just anyone who can't cut it at the local Arby's?
Anyone?