They intentionally made Demise to resemble Ganondorf somewhat, but only because Demise's Hate Curse is supposed to be the explanation behind Ganondorf's resurrections. I've seen many people think of it like Ganondorf is literally Demise reincarnated, but most theorists generally accept this isn't the case. It's completely different to say my Hatred will reincarnate rather than just I will reincarnate.Oh, well, that's something else then. I always pegged them as being the same person. I mean, it's curious that both Demise and Ganondorf have red hair, a striking physical characteristic. What are the odds?
I'll read that blog entry though and get back to you with what I think about it.