The average person walks approximately 5 to 10 miles a day around Disney World. And yes I know if you get tired you can take a break inside an air-conditioned building if needed.
I think what will go a long way for most people will be three things,
1. A covered or partial covered walk way
2. Benches or a place to sit so people can stop and rest if needed
3. Cold water stations so people can get a drink if needed
I am sure Disney is reading not only comments from the online community but also the guest surveys.
If enough people mention the long walk on the pier I am sure Disney will do something about it, remember this is a new concept for them with it not being their own private Island.