Stellar is not a cryptocurrency. It's only partially decentralized (like Ripple) - there is no blockchain, it works with a series of trusted nodes. That makes it very easy to have fast transactions, but also makes people not very confident in it.
Also, they make me sign in with Facebook to claim Stellar (in their latest PR campaign). No.
If it uses trusted nodes why not just use Chaumian Cash, and have the trusted nodes be issuers, rather than reinvent the wheel? Chaumian Cash is perfect if you don't care about decentralization.