I already know a lot of younger folks that are pumped about the Snapchat glasses...
(I'm not saying you're wrong... I just wouldn't make such steadfast predictions about the future either. But then again, I don't understand SnapChat and am not their target audience.)
You need to be right about half of successes, which is much harder for a raging pessimist like OP.
If your friends aren't using them and you're the only one with a pair you'd be less inclined to wear them. Everyone thought Google Glass was going to be the future but those glasses made you look like a total douche. Hopefully the Spectacles wont be branded as such.
Glass definitely failed in the marketing, branding, and roll-out departments (among others) -- but they're no more or less doofy (to me) than many other perfectly-accepted fashions: baggy pants, beats headphones, crocs, etc.
That is a fairly small focus group.
If the glasses are promoted as something you only wear when you want to record video and that you otherwise put away it might take off.
Nobody minds when you pull out a cell phone and record video because it's obvious you're filming. I think it was the omnipresent threat of being secretly recorded that made Glass creepy.
If Snapchat sets up the glasses business as an additional revenue stream, it could well become a reasonable but limited success, if they set it up "strategically", maybe even selling at loss, I predict terrible failure.
I mean that's a bet with a payoff & loss.
I'm not really knowledgeable about the "wearable" market, but to me it doesn't seem as ubiquitous as the smart phone.