Most of the locals favor anyone with money. It's just an issue of tolerance. If it weren't for the money foreigners bring in, the majority of the locals wouldn't really tolerate or want to communicate with any of us. They also don't share the same curiosity to learn about other people and their cultures the same way that locals might take more of an interest in those things when one travels to other countries.
In addition, they don't really understand the cultural, religious, political, or historical differences between the various tourist ethnicities that come here. The things they notice are appearance, hygiene, skin color, behavior and politeness. That's how they separate most of us ethnically.
The one thing that sets one foreigner a bit apart from another to them on an individual level is the degree in which one can speak Thai and communicate with them. And since they really only want superficial contact with foreigners in general, it means that things like smiles, body language, good manners, and generosity is often what gains the most appreciation from them.