Interesting hypothesis, but I'm not sure I buy it. Saying every company that uses tech is now a tech company I think is just misunderstanding what 'tech' is. He's conflating companies that produce tech with companies that consume tech.
Now it's true that there is a lot of free tech out there now. Open source technology is allowing companies to automate more and more, but that doesn't change the underlying sector of a particular company. A company that is in agriculture has to invest in tech to stay competitive. (ie it has to buy tech/ hire the grunts to implement it), but these usually aren't the companies making this tech. Tech companies are in the business of producing and improving tech. And yes, large parts of the tech market are commoditized, but that's been true for many many years now. Laptops/Desktops haven't had good margins since probably 2005. Yet somehow, companies like HP continue to make billions off them. But this just means tech needs to revert back to a p/e of 16 not 30-40.
Are some tech companies overvalued? Absolutely. He's asking a good question in there. Why the inflated value of Amazon, Apple, etc. They cannot and won't maintain the growth they've had in the past couple decades. Apple's stock seems to have mean reverted with their p/e hanging at around 13. That seems like a reasonable price for a company that will continue to make a good profit. Amazon I believe is still overvalued. They have AWS, but wait until switching clouds becomes easy and commoditized. You also currently have MSFT, HPE, IBM, etc. all playing in the cloud services space with AAPL looking to join as well. That'll bring margins down, and tap out at some point. The cloud services space is still a bit wild west, but the industry will eventually consolidate on 1 or 2 unifying technologies that will make them all more or less the same.
Do you expect manufacturers to be buying robots? Yes. But that doesn't make them tech companies that makes them consumers of tech. We don't call Walmart a transportation company just because they move stuff around. They move stuff around because they sell consumer goods. The same goes for agriculture: do they invest in tech? Yes. Are they selling tech? No. Their tech is an end to a particular means. Namely cheaper production of agriculture.
Don't muddy the waters, this isn't difficult to keep separated.