Because it's the only Bitcoin 2.0 that, together with Codius, will make it in the real world.
Bitcoin 1.0 has to many issues, Stellar died last week & Ethereum is to complicated and to slow.
Ethereum is going to be the altcoin killer. Vitalik was able to clone CounterParty on Ethereum in 4 hours. After it comes out any kind of innovation by any other platform can immediately be cloned and added to Ethereum. But Ethereum can also be cloned, so that is a bit of a problem.
Also, Ripple isn't really a 2.0