Wiki suggests the need for a moody host was dropped in some later international versions of the show, though in fairness Anne Robinson did lighten up a little bit at some point but was still predominately moody. The later change to the end game question delivery was very much needed though.
Mind you having a moody host as opposed to a stereotypical happier-than-thou host could have been interesting for some other gameshow formats.
I do think the "moody" theme in gameshows really needs to finally snuff it. The Chase just about manages to get away with it thanks to the banter from Bradley and the Chasers, but even shows like Who Dares Wins still have these horribly dramatic musical stings that, IMO, dates it horribly. I know if you go in the opposite direction you risk the show being cheesy and naff, but it'd still be a nice change.