Ethereum is the perfect foundation for DAOs for a number of reasons:

• Ethereum’s own consensus is distributed and established enough for organizations to trust the network.
• Smart contract code can’t be modified once live, even by its owners. This allows the DAO to run by the rules it was programmed with.
• Smart contracts can send/receive funds. Without this you'd need a trusted intermediary to manage group funds.
• The Ethereum community has proven to be more collaborative than competitive, allowing for best practices and support systems to emerge quickly.