Those are good points askubel, and that's exactly why CSR developed the CSRmesh, but with a lighter protocol that does support thousands of devices - it looks like the engineers at CSR and Nest were looking at similar solutions from different directions at the same time, which is why we end up in this kind of situation.
It will be interesting to see CSRmesh opened up as the company has said, but Thread also needs to be an open protocol.
Then I suspect there's an opportunity for smart ways to provide a multi-protocol solution without the resource overhead - that's the kind of thinking that Imagination Technologies is following with its auto-discovery and configuration approach.
These responses are missing the point. Yes, BT Smart has IPv6. Yes, it's low power. Yes, you can make a mesh network with it.
Do they really think the engineers at Nest didn't think about that? Creating a new standard is a massive job that will face a lot of resistance. They didn't just make Thread up for fun or to have a proprietary ecosystem to lock out competitors.
I don't know exactly why BT smart wasn't good enough. What I suspect, is that while it is possible to build a mesh network with Bluetooth it isn't possible to do so with the extremely minimal power consumption promised by Thread, and I also suspect it isn't possible to build an efficient BT Smart mesh network that can scale to over 250 devices.