I don't know if more people is a driver.
I am BWV owner and that is where we usually stay. I often take the path from BWV to DHS. That path is there, and its usually deserted, even with all the Epcot resort. Sometimes I see one or maybe two other people taking that path.
We usually eat over at the Contemporary on a MK day, and we've made that walk a few times - it isn't my favorite walk - more "street" than path - it compares unfavorably to the BWV/DHS walk which is not great by any stretch. But once you get past the buses, there aren't a lot of walkers. Even when we've done the "its closing time, lets walk over to the CR and catch a cab rather than deal with the buses" it isn't exactly a popular walk.
We've done the walk between SSR and DTD, too - that wasn't exactly rush hour.
The simple truth is that these paths don't get used much - other than the BW/BC path to Epcot (even there, there are FAR more people waiting for the boat each morning to Epcot than bodies on the path from the BW - and at closing time, its only worse). If they are put in as part of the original design, they exist. But once the original capital is spent, Disney can't justify them for the use they get.