Bitcoin has a number of properties that give it utility (and thus value) such as trustlessness, permissionlessness, transparency, and immutability.
When you broaden your perspective of bitcoin from a currency and payment system to that of a secure historical ledger, it becomes clear that these properties, in conjunction with each other, can enable powerful applications.
As the "blockchain but not bitcoin" buzz continues to intensify, we can see that this is because many existing business and financial use cases don’t see a need for trustlessness and permissionlessness. Traditional financial institutions already have semi-trusted permissioned relationships that they have been established over many decades and their goal is to reestablish these relationships with new technology that makes coordination more efficient and robust. Public ledgers like bitcoin have been problematic for financial institutions because transaction validation is performed by a group of potentially unknown parties while financial institutions are often legally required to vet every transaction going through them.
Some of bitcoin's properties are difficult to describe comprehensively.
While permissionlessness (anyone can use the system without asking permission or fear of being censored) and transparency (anyone can audit the ledger) are straightforward, trustlessness and immutability are more complex.
SOURCE: http://www.coindesk.com/bitcoin-the-trust-anchor-in-a-sea-of-blockchains/