Don't think that is true anymore ... there are lots of qualified Malaysians, Indonesians, Indians and Pakistanis who will work for $10 an hour and be happy about it.
Speaking from experience, there are a lot of people looking for Westerners with a $40-60/ hour budget, which is too cheap for Westerners and too expensive for South Asians. It doesn't have to do with qualification, it has to do with reverse discrimination. Their ideal is to get Westerners at a discount, because whether right or wrong these people perceive trust, communication, and quality to be greater working with a Westerner even, if that Westerner is working out of hostels and coffee shops.