Was probably a forced backroom deal type of thing that there had to be the same fee on btc as credit providers.
I imagine visa/mastercard and all those guys would cancel your account otherwise and then the only way to buy a ticket on your airline is bank transfer or bitcoins. The big dogs still have everyone buy the balls.
And if you look at their card they are actually in partnership with visa so visa would have just said keep the fees the same and we'll allow you to accept btcs.