Its not clear to me that raising the blocksize wouldn't cause massive amounts of node centralization. If right now running a node can be a problem for a lot of people, if you make the blockchain grow at twice the speed, I think it's going to be really hard to run a node. We need data before doing this, and the research done so far points at centralization of nodes.
Just to show how silly this argument is, right now you can buy a 6 TB hard disk for 270 euros, any computer you buy comes with at least 1 TB hard disk, 10 years of 2 MB blocks are approximately 1 TB, I think, right now, at least when it comes to storage we can afford 8 MB blocks...
Imagine how cheap storage will be in 5 years, in 10 years, plus optimizations made to the protocol.
People bitching about block chain size and delaying adoption because of this is just silly.