Not enough profit for the conglomerates. The problem with tech these days is that it breaks so fast. Which is the result of removing lead. Circuits are brittle not pliable anymore so they don't last long. Especially when mobile.
The idea is pretty amazing. You want a big screen phone? Grab a big screen module! You want an awesome camera? Grab that module too! It is pretty awesome what can be done with those blocks but I don't see that working economically. People don't really want to build their own phone, they want one that's ready to use and has the most features. I know I would prefer getting a Samsung or an iPhone over one of those phoneblocks.
I KNEW it was a kickstarter! I saw that coming a mile off. "We've got a moderately cool idea, but no idea how to do it, please give us money." Another thought I had during the presentation was that it was somebody getting a degree in media or something, marketing and obviously impossible product. It's a nice idea but ultimately impractical. It's like they've taken the idea of one of those Arduenio? boards and gotten carried away. Components like those in a mobile phone do not interact in that way. They all require different voltages, and need different data channels to various areas of the phone. The infrastructure on that level could not possibly support a modular configuration in such a manner. This is all without the idea that the FCC and similar bodies would likely have a massive issue with this sort of thing. Assembling your own mobile phone without any testing sounds like something they would not approve. I think this is a cute idea, but there are too many practical considerations for it to become a thing in any of our lifetimes. Besides, it's a niche market. Who wants to build their own flimsy ass lego phone? Even the most hardcore of my geeky friends prefer something a bit more... professional. Saying you made your own computer is cool, if somebody told me they made their own phone, right now I'd think they were weird. Sort of like the people 50 years ago that made their own radios.
Can't help but think of this after your post @CelarD Couldn't they all more pins or contact points for the components and take care of some of those issues?
With how small things are now, it's not practical. I firmly believe that there is literally no way to make such a modular system work with current technology. For all the reasons I said above I'm not ruling it out, but I am certain that as of now that technology does not exist. And nobody would care if it did. edit: The pessimist is never disappointed, so he may be considered an optimist.
I do not see why you think it is not practical or possible. I mean I myself could probably build something very similar. It would not be difficult to make all the parts universal, voltage is something very easy to regulate. And with chips being smaller and smaller these days, that is not a problem. As for as what you talk about concerning the traces and such, again that could easily be accounted for. The idea is not impossible, but I just do not see any of the major companies backing the idea. As for as it not being doable that is silly though. The technology does exist. We can rebuild, we can make it bigger, faster, stronger....