The early web had what was in retrospect an astonishing degree of transparency, it took very little effort for anybody to become a web developer -- this isn't an argument for its etymology but I wouldn't be half surprised if "web developer" came to be coined as a kind of intermediate tier between "computer user" and "programmer", what with HTML being a markup language, making room in the engineers' office for people without STEM backgrounds but stopping short of granting them peer status.