“We first put Rumplestiltskin [Robert Carlyle] in a hoodie. He looked simple and very non-threatening. Then [the producers] said, ‘Let’s make him a rock star.’ We redesigned his look from head to foot, thinking of Keith Richards and Mick Jagger. Now he looks sexier and more dangerous!” (source: TV Guide)

The same logic went into Jareth the Goblin King. It is flawless logic.