You really have to put things in context. Back then, there were three over-the-air networks and the first cable networks were in their infancy (and with no money for Olympic coverage rights). Also, TV coverage of sports in those days was not the spectacle it is now. ABC certainly had doubts about pre-empting the daytime soaps for Olympic coverage. It also should be noted, they actually scheduled slightly more total hours of Montreal coverage than they planned for Munich; but clearly Munich was such a success for them they didn't think they needed to make huge changes to the winning formula. Last point: there was much less interest then in the daytime qualifying heats in track and swimming than there is now and (because Montreal is in the Eastern time zone) any daytime coverage would have been kind of uninteresting.
Frankly, I enjoyed watching the coverage in those days. The evening shows from Munich were tightly edited and packed with action (in part because just about everything was on tape delay for the U.S.). Montreal coverage was good because it had lots of truly LIVE stuff in the evening. These days, with so many hours to fill, the networks show a lot of filler -- even when the events are on tape delay. The real travesty was Atlanta, when NBC decided to delay stuff they could have shown live in the early evening just so they could tease viewers in the east all night and allow the west coasters to get home from work and finish dinner.
One of the big controversies in 1996 was NBC showing the gymnastics on tape delay. HOWEVER that was not a case of NBC holding on to an event until primetime. NBC would have MUCH preferred that they have it live in prime time. Gut in one of the few cases where the Europeans got what they wanted the gymnastics was scheduled around prime time in Europe so they got a marquee event while NBC had to tape delay an event they wanted live(and felt they should get live since the games were in the US)