Sure, and I think this problem of transferring small amounts of money internationally painlessly is probably the strongest case for cryptocurrencies. But:

1) I don't think that's what cryptocurrencies want to be relegated to (a forex market essentially)

2) This also seems like a way around currency controls and things like AML compliance. If that became a problem at some point, I have to imagine governments will start putting the screws on any major exchange that interacts with fiat (and to some extent they already have).