Excepting the moon landing comparison which has already been thoroughly decried, this post is spot on. The phenomenon really shows the importance of connotations, associations, and learning to present yourself effectively.
My personal experience has been that the label "web developer" is typically used by less experienced people if only because after a little while in the industry, even if your focus is primarily web-related, you start to develop skills that are more widely applicable and don't want to be "pigeonholed". It doesn't have anything to do with the difficulty of the problem set, the quality of the ecosystem, or any other specific value judgment.
It's the difference between a package delivery service characterizing their employees as "box movers" v. "logistics coordinators".