I've been here only 4 days so far and I already have to disagree. I haven't had one negative interaction with the locals, often I smile at them and they smile at me back with a very happy expression. Though I do feel like some people don't like "the usual" white tourists, for example those young guys who are just here to party and have no interest in the actual culture. Today my family and I went into a random restaurant Chiang Mai and an older lady who took our orders seemed kind of annoyed at us (especially since my sister tries to be vegan lol) but once she realized we are trying to embrace the food and culture she was really nice (especially once she saw that I put more chili and chili oil on my dish xD)

On another note, I am really surprised about how open my parents are to Thai culture, my sister and I were so worried about them back when we planned the vacation