Due to the liminal nature of the shuttle rides, you are bound to miss some aspects that would otherwise be encountered on foot. Being sequestered in a metal container and moving at speed disconnects you from your surroundings. Additionally, the anti-social nature of the bus makes one less inquisitive about their surroundings as they turn their focus inwards. The environments in liminal spaces are not conducive to having a deep experience with one’s surroundings.
The biggest aspect of the experience that is missing is the flaneur. If one was walking to Harvard rather than taking the shuttle, they would have a greater interaction with their environment. When one is hurtling through the city in a metal box there is not as great on an opportunity to soak up the culture. For example, if I find a specific section of Harvard Square more interesting I am likely to linger there. Without direct intent, I will absorb the stimuli around me. In areas I do not find interesting, I am likely to breeze through without taking them in.
Simply by having the freedom to vary my pace through the city I am able to interact to a greater or lesser extent with my environment. In the bus, the freedom of pace is lost. Compounding that loss with the high speed, I have almost no interaction with my environment. While the shuttle may have been the simplest way to get to Harvard, it definitely was not the most engaging.