No, I can understand why the embassy do not want to accept that as a proof of funds, because anyone can bring a wallet a show a balance and then transfer those funds back to their friends after they received approval for their VISA application.

The Banking industry are very regulated and a credit card application goes through a lot of "red tape" to be approved, so they trust that process and also the credit it provides.

Bitcoin for the most part are still very unregulated, so governments do not trust it..... yet.