While I agree with you, there are some issues with going back to standby only.
First of all, most of what has been added to Disney in the past couple of decades do not have the hourly capacity of the people eaters they built at EPCOT and for some of the MK (Pirates, Haunted Mansion, Small World). Secondly, the number of people in the parks on a daily basis are much higher than they were back in the 90s. Since Disney hasn't increased capacity enough (between lack of new rides in general and lower capacity on many of the ones that have been built), wait lines are going to be much longer.
It won't be the way it was back in the 90s glory days unless Disney somehow lowers attendance or goes on a major building spree to add significant capacity.