Every artist learns through imitation, but I rather doubt the aim of these things is artistic development. I assume they're either homages or satiric riffs, and are not intended to be taken too seriously as works in their own right. Otherwise I should be talking to a copyright lawyer.
Bill WattersonCalvin:"It says here that 'religion is the opiate of the masses.'...what do you suppose that means?" Television: "...it means that Karl Marx hadn't seen anything yet
Bill Watterson