What I find most infuriating is this attitude that, hey, this idea of mine is maybe theoretically possible, so let's make a shiny, over-stylized concept video to promote it as though it's practically been built already. Because I've done the
hard part and come up with an
idea. And now all we need to do is get the right companies and the right people together, and this whole thing will magically fall into place.
The negative reaction that this video has engendered from myself and others is due mostly to the fact that its creator appears completely oblivious to the challenges inherent in what they want to make, including all the reasons that – at least on the face of it – this idea is a complete non-starter; and yet they dress this up and present it to the world with complete confidence, as a sure thing on the cusp of taking shape. This drastically over-values a design concept and brushes actual engineering effort under the rug as a simple matter of getting people and money into the same room. And it misses the forest (reducing waste and cost of ownership, increasing device durability and longevity) for the trees (an overly-complex modular design which would actually be detrimental to all of the above).
Incidentally, I take your comment about using 802.11 as a system bus (!) in a similar vein. You make an enormous leap from observing that something might be made to work in theory, given sufficiently fuzzy constraints, to making concrete assertions like "you're looking at something that can be shrunk down to well within the scale Phonebloks needs, for pennies a block" (well no, not if those blocks need OFDM modulators and network stacks and zeroconf implementations). Nevermind all the more fundamental reasons that Wi-Fi is not a sane choice for a system bus (latency, EMI, power consumption, complexity of numerous unnecessary abstraction layers to name a few). Something which is possible in theory can also be a horrible idea in practice, and it's disappointing how many people have trouble with that distinction.
[By analogy, one of the challenges we'll face in sending humans to Mars is the 26-month periodic launch window created by the planetary orbits, which imposes extra constraints on any mission plan. But wait, in theory we could build a rocket big enough to take us back home even outside one of these launch windows, right? I certainly don't know enough about astronomy or rocket science to say otherwise. But I'm also aware enough of my own ignorance in those fields to skip calling up NASA and insisting that they get us to Mars sooner by building bigger rockets.]
The point is that if you're going to make a promotional video apparently designed to attract investment in your idea, the burden of proof is on you to show that your idea is reasonable. And if people with actual domain knowledge then come along and point out numerous basic problems with your strongly-asserted idea, it isn't "knee-jerk negativity" but a much-needed dose of reality.
> there's a saying: those saying something can't be done should stay out of the way of those doing it.
The Phonebloks designer(s) aren't doing it. Someone made a promotional video. Huge difference. And the people who actually would have the expertise to do it are saying, not quite "this shouldn't be done" as you lament, but something more like "the inherent tradeoffs that the designer has ignored make this not a good avenue to pursue given the design goals and engineering realities, and the designer is clearly way out of their depth for neither recognizing this themselves nor consulting anyone who could".