If I am not mistaken, Thunderbolt is still exclusive to Macs? THAT is the reason it is a total failure. There are so few people using them, relatively speaking, that there is not a potential to reach hundreds of millions of users you could target if this went to PC. It's good technology, but it is essentially proprietary.
It just recently began showing up on PCs. It's Intel's standard to control, Apple just had a one-year exclusive deal to it.