People who remit bitcoin from the US /UK or Canada would buy BTC at the prevailing market rates at the ATM (I assume this, maybe use one of the major exchanges as a benchmark), the moment they remit this money in BTC to folks in India or Asian countries, we do not have an atm / money exchanger who would immediately convert BTC to Fiat. Hence we put the coins up on LocalBitcoins AT A PREMIUM to market rates.
There is already a bitcoin-based remittance service for the Philippines: The sender gives them USD in the US, they use the USD to buy bitcoins at the exchanges, then sell the bitcoins in the Philippines for PHP, and give the PHP to the receiver.
Not long ago they posted to /r/bitcoin calling for help, because they had run out of OTC buyers in the Philippines, and they could only sell them on the local open market BELOW the equivalent of the USD market price, hence at a loss.
That is a general problem with bitcoin-based remittance: in order to sustain the local price, there must be a return channel that buys bitcoins at the destination country, with local currency, and sells them back at the exchanges for USD. Arbitragers could do that, profiting from the spread between the depressed local price an the USD market; but they would soon need to convert the USD that they get at the exchanges back into the local currency. But if the arbitragers have a way to do that and still make a profit, then a remittance service could use the same way, and undercut the bitcoin-based service...