It's not a decentralized exchange. It's an open sourced exchange. It will be up to entrepreneurs to take the buttercoin code and set it up as the engine for the

It's not a decentralized exchange. It's an open sourced exchange. It will be up to entrepreneurs to take the buttercoin code and set it up as the engine for their exchanges. The majority of the work will not be in the systems, but in setting up the exchange as a proper legal entity. There is significant cost in operating in the US, because you have to register as an MSB at the fed level, plus once with each state. Fees run in the thousands per state, per year. So I think the OP's question was why there aren't decentralized exchanges. I took that to mean why there aren't P2P style exchanges. I'm not sure what the answer is. I think people have been tossing that idea around for a while but I'm not sure if they have started code for it. There are many exchanges now, but for some reason people choose to use MtGox, which is AWFUL.