I'm surprised that nobody else has brought this up: No less an authority on matters arid and wild than Edward Abbey has written extensively [0-1] on the inaccessibility and remoteness of the Grand Canyon. If I had to sum up his position on this topic, it might be "That's the point."
You can simply drive to the rim. The entire path around the rim is paved and handicap-accessible. You can take a mule into the canyon. It's difficult to get to only in the sense that you must drive for several hours from any nearby city to reach the area.
Yes, because only the able-bodied should be able to enjoy the richness of the region.