I would have preferred that too - or many just a storyline where he werewolf side was changing, like we kinda saw in Fear Itself, where he might start changing without a full moon & the rules seemed to be changing the longer he was a werewolf & then he'd go off to try & find others like him & understand what was happening.

But I don't think they would have wanted to do that though, because then Willow might have seemed like the bad guy & they wanted to make Oz one instead