Many exporters (and I guess importers as well) are essentially in the same conditions. For proper accounting and paying taxes they have to convert their export proceeds in foreign currency from that currency into their national currency. They may also have to sell some part of the profits earned to a local central bank or on the currency market. In my opinion, Bitcoin as a means of payment and currency in its own right should be treated accordingly, i.e. as a foreign currency...
Until governments decide to use Bitcoin as a legal tender, of course
the other thing is that government are familiar with this process with the big currencies. if you have an unusual currency or bitcoin it is somehow harder for them to deal with it. just for tax purposes they have daily exchange rates you can use and nobody will question this, but with bitcoin you would need to do extra work and prove and document everything. nobody likes extra work.