Yeah, Chuck hit on a lot of it...

China has a lot of teachers from the Philippines, West Africa, India/Pakistan, and so on. Many of these folks ARE native speakers, and many are fine, well-qualified, experienced teachers. However, due to their race and national origin many of these people have had to struggle to find work in China...many schools, students, parents, etc. seriously believe that "real English" is spoken and taught only by white people.

As a result, a lot of these people work for lower salaries in poorer conditions than their Caucasian counterparts from the Big 7 English-speaking countries. They are less prone to complain and to stand up to abuse...they simply have fewer alternatives.

So, sadly, a lot of these job ads specifying Filipinos, etc. are really saying "We want someone who will work dirt-cheap, and who will take our abuse without making a lot of noise about it." It's a BAD sign. And I wish it weren't the truth...