Bill's a one-writer character (in what has been a very well-received story), and he's not really that important to the Thor mythos or to Thor himself (in fact, I can't recall the two of them ever even meeting). Skurge was by comparison way more significant, and he's stayed dead for a quarter-century on the strength of a really strong exit. Resurrections are mostly for characters who've been around for a while and have a definitive place in the minds of writers from their childhoods.