Does Windows 8 really have to be a roaring success straight out of the gate, I'm pretty sure CDs weren't and from memory DVDs were even slower.
People are sometimes slow to adapt to new ways, that doesn't necessarily mean that they're a failure.
People hated XP and Windows 7, have a look at them now. Windows 8 is a huge step from either of these two so its only natural there's going to be some hesitation.
I breed Tropical Fish and have bred parrots, when you introduce a new food, doesn't matter how scrumptious looking, these animals reel back and are very suspicious. It can take days before they accept the new food. Although not all of them are like that, some are bolder than others, possibly Alpha Males.
Computers themselves didn't exactly start off with a bang, I was the only guy I knew for years with computers, long before they became popular.