When any company start accepting bitcoin they have to need many reasons to accept it.Don't worry sooner or later they will accept it..
Well the thing with BTC is that it is faster and they save a ton of money on fees.
I'm guessing the only thing that is scaring them away right now is the volatility of BTC. Unless they instantly sell they can't guarantee that they will get the amount of FIAT that was paid using BTC.