So first, the financing environment is different than than Generation Google's. By this size, Google had (arguably) the proven-best online ad business, the (inarguably) most impoirtant web page, and a big deal IPO. Magic have that kind of money in stealth mode, with no real reason to speak to the public. Regardless of the "how we build things" philosophy, Google's generation simply could not have got to such a scale before interacting with consumers. There just isn't a precedent because this environment is new.
I think what you're asking is questions that Google's generation would have got (based on previous generations' schools of thought): what is AR's "killer app," the lotus notes to it's personal computer. Before those existed in users' hands, home computers were pitched as ways of organizing personal finances and recipes.
Anyway, I think you're right. The hows and whys of AR becoming important are all very vague. I suppose that most of Magic Leap's pitch (to themselves and investors) is centred on the technology itself, not its application.
The article suggests investors think of them as an intel, not an apple.
Whether or not that's a mistake, it does leave the most interesting (to us) questions still open. What is AR for?