No, the work of Walt Disney himself. Walt knew how to tell a story without superfluous elements and the 1953 Peter Pan movie was 76 minutes in length. Walt knew that rides in his park should be short. The gold standard for rides is the Matterhorn Bobsled. One track runs a little over two minutes while the other runs about two minutes and a half. It's a Small World runs eight minutes and Space Mountain runs three minutes. The Jungle Cruise only runs seven minutes. I'm sure they can improve upon those times and shorten things a bit.
Disney learned with attractions such as Horizons, Journey into Imagination and WoM that they had created Omnimover overkill since Spaceship Earth was close by as well. They realized they were boring people to death with so many long rides concentrated in such a small area. Thank goodness they got rid of the most boring and modified the others to make things interesting again.