If we talk about bitcoin deficiency means we are talking about its weakness, I think this is the weakness of bitcoin:

1. Not Stable
Bitcoin is a speculative currency. Currently not enough companies that offer the purchase and sale of products with bitcoin as a means of payment.

2. Very risky lost or stolen
As a virtual currency, bitcoins are encapsulated in the form of digital files or known as wallet files. In use, the wallet file is similar to the cash register function.

But the wallet files stored on the hard disk of your electronic equipment are very vulnerable to damage. In addition, viruses that attack your hard disk can also make stored bitcoins just disappear.

3. Money laundering tool
The use of bitcoin currency is not controlled by the government or authorized financial institution. As a result, such conditions provide great opportunities for criminal activities such as money laundering and tax evasion.