As someone who was looking forward to getting a consumer version of Glass, I get a special schadenfreude looking back at all the articles saying how obvious it was that Spectacles would succeed where Google failed.
Looking at the profiles of the two top-voted comments in that thread, that doesn't seem to be the case. But just browse the replies: many HN posters genuinely seemed to believe they'd nailed some key niche and important product details. They didn't strike me that way -- which is why I remembered the post.
The contrast struck me as an interesting example of hindsight bias.
https://news.ycombinator.com/item?id=12569182
and compare those to the "it was obviously going to fail" responses here.