In defense of Worldedit and its ilk, a lot of great things can be made with them, but the actual sections to buildings still have to be made by hand. It allows you to do things that would be absolutely excruciating in Survival and still incredibly time-consuming in Creative. It doesn't create something out of scratch. Like Creative, it just removes a lot of the monotony. There's a point where grinding and/or more time building is unhealthy, and this provides an answer to that.
Disclaimer: I understand that this is a joke and not meant to be taken as a legitimate argument; I just felt that generation software needed a little more love.