And, funnily enough, Windows tablets can do that today, and the phones get it with Windows 10.
(It's hard to read the market's mind. But every once in a while, you can guess where it's going to go in advance... and get yourself brutally murdered in your financials when you show up to the party years before the money shows up.)
Back on the topic of the original article, it's possible this is Microsoft's core strategic play... if they agree with me that this is inevitable, they've still got the income and the OS resources to stick out the market's slowness, and build an incredible offering on this front out with all their resources. It's at least possible that they could indeed unseat an incumbent Android/Apple duopoly if they can be that much better than the competition once this use case becomes big... and it's not hard to imagine it going down that way. They've got a lot of cards on this front that even now Apple and Google do not, games, for instance.
Supporting older hardware, too. The fact every Windows 8 Nokia is getting a Win 8 upgrade contrasts pretty well with the way my Android 5 device won't be getting a patch for a critical security vulnerability.
Due to the mobile form factor there are certain use cases that it simply can not fit while still being a "phone". This is not because the phone will lack processing power, it's literally because the form factor just can't have enough input & output options. Barring major battery upgrades, it also literally lacks the power to solve all problems. The extra hardware will also have laptop- or desktop-class heat dissipation capabilities, which a smart phone simply can not solve without, again, being something other than a phone when it's being a phone.
That is all to say, there are real and specific reasons that phones can't eat all the use cases the way minicomputers ate mainframes and desktops ate minicomputers. The only way for phones to eat all the use cases is to hybridize "back" a step and also become the things it is replacing again.
We've seen some abortive attempts at this. I find myself wondering if the fundamentally closed nature of the major phone operating systems is inhibiting the creation of this stuff, because the requisite OS changes to make this work are too hard. While I don't own one I still find myself rooting for the Firefox phone or the Ubuntu phone... they've still got a chance to beat the other guys to this market. And I for one would hate to sacrifice the openness of my entire computing stack because "the phone", which at this point will be little more than "one particular app", is closed. That's an awful lot to sacrifice to an increasingly minor use case.