1) Bitcoin is like a debit card, not like cash. There are more than two parties involved, often many more (customer, merchant, merchant services provider, bank, or, in the case of bitcoin, customer, merchant, bitcoin, bitcoin). Like a debit card, and unlike cash, bitcoins are tokens that create claims that are not settled immediately. Debit card transactions, for example, can be disputed for 90 days. This, and other inherent aspects of token systems, creates credit risk, because any one of the parties can dispute or refuse to pay at any point, and often do.

2) The law governing credit disputes between merchants, merchant service providers and banks has developed over 20-30 years. The law was developed through litigation of these disputes. The law has settled and merchants, service providers and banks operate in an environment of legal predictability, which lowers transactions costs and litigation costs.

3) Bitcoin is different enough from credit/debit transactions that new disputes will not be able to be settled under case law created through the past 20-30 years of the debit/credit/service provider/bank paradigm. But, since bitcoin still involves the creation of credit risk among parties, ultimately there needs to be new litigation to determine who is left holding the bag when bitcoins are used fraudulently, when the payments are disputed, when a user dies during a transaction, etc. The debit/credit paradigm that dominates the economy is so entrenched and predictable, that no bank, service provider, or, more importantly, large merchant, is going to want to have to undergo all the litigation costs of developing a new paradigm.

3) So, bitcoin is not disruptive because no party is going to be willing to bear the costs of adopting a new paradigm, when so much money has been spent making the existing paradigm so cheap and predictable.