I see it as a failure to capture value. Your belief is based on the perfect market hypothesis ("If there were a way to capture value from those employees someone would be doing it") but the landscape is changing so fast due to software, I just don't think you can make that claim.
I think the old systems of employment have mostly run their course and are on the decline, but new systems based on loosely federated networks of independent contractors will replace them. Right now the tools are weak, but will get better. So we're in a kind of gap right now, where the old system has optimized on a local maximum that is leading to unemployment, but the new system hasn't quite formed to take over those employees. Increased unemployment will increase the pressure for the tools to stand up.
What makes you think the new system will be sustainable, or loosely federated? If we go by the known examples of Uber and AirBnB, the new tools produce environments where power is even more concentrated, and independent contractors are squeezed to the lowest viable income levels by competition.
And what are the dynamics of this new system upon which the GP can assume that everyone will find a place in it?
How many people has Google Apps for Business already put out of work? I've "gigged" setting up this sort of thing for small companies with Linux, and continue to do it for my medium-sized church. However, this market has changed DRAMATICALLY within the past 5 years. My church payed the money to switch. Even the Fortune 150 I work for has now outsourced its email and messaging, from in-house Notes, to hosted Office365. That represents HUNDREDS of internal admins that are simply no longer needed in one of the largest manufacturers in the country. Even someone with experience and specialized knowledge in basic networking and services (email/file & print/DNS/DHCP) will have a hard time finding "gigs" going forward with Google Apps and Office365 in the market. It's just too easy! A kid who grew up with a smartphone is all you need to set it up.
We, as a society, are already leveraging the efforts of a relative tiny few to alleviate the work of thousands, even hundreds of thousands, just in IT services, and this grows exponentially by the year. Twenty years ago, the trade mags were raging on "cloud" everything. It took 10 years to figure out that it just meant "someone else's computer." Now it means a web portal to configure everything you need and take your money.
I'm also good at hardware (microcontroller-based machines) and business domain programming. Sure, I figure I'll have work until I'm dead, but I see what's happening with Arduinos and Raspberry Pis, and the "internet of things." I know it's crap, but when Joe Blow can buy the junk from Amazon, throw it in his home and office, and it does essentially what it's supposed to do, what's the difference to him? That trend is also going to continue to scale out so that more and more things that would have taken custom hardware and software will be recognized as a market need, and product-ized.
At each step, more and more people just aren't needed to make what everyone wants or needs, because of market dynamics like the parent alludes to: all home appliances being made by less than a handful of companies. All entertainment being copyrighted by 4 companies. All IT being controlled by about 6. All cell services in the hands of (essentially) 2. All broadband in 4. On and on it goes. All endeavors trend towards monopoly in a capitalistic system, and I don't see any way for the US government to reign that in at this point, with regulatory capture being operative phrase of the day.
I'm glad someone's hopeful about how my grandchildren are going to find their place in society. I'm holding my breath.
I think the old systems of employment have mostly run their course and are on the decline, but new systems based on loosely federated networks of independent contractors will replace them. Right now the tools are weak, but will get better. So we're in a kind of gap right now, where the old system has optimized on a local maximum that is leading to unemployment, but the new system hasn't quite formed to take over those employees. Increased unemployment will increase the pressure for the tools to stand up.