-Credit card issuers have a right to limit their credit risk and fraud losses.
-Bitcoin is behaving like a speculative bubble. The definition of which is:
“A large upward move in an asset’s price driven not by the asset’s fundamentals—that is, by the earnings derivable from the asset—but rather by mere speculation that someone else will be willing to pay a higher price for it"
1-From a fraud loss point of view, it's extremely easy to buy Bitcoins through Square (https://goo.gl/ia1B8y) a perfectly safe site.
2-Banks should increase their due diligence on the sites for which they process payments, if fraud worries them.
3-As a cardmember, a bank unilaterally decidingwhat I can and I cannot buy worries me.