Biggest hurdle is fear of loss of face, most Thais wont say a word unless they are sure its perfect.
I tried to introduce more use of audio visuals when I was teaching because its no sectret kids cant take their eyes of a screen even if its just the weather. I was refused because the school believed the parents would complain the teachers are just being lazy by letting the kids watch TV??
I dont think its so much resentment as nationalism, Thailand is perfect, the biggest and best country in the world, best food etc etc. Why learn an inferior language? Anyhow Prayut said the rest of the world will speak Thai soon.