You make some disparaging, hurtful but somewhat accurate points. Thai students range in effort from bored to extremely interested in learning English. Why, and here I think you are correct. They do not understand that having the ability to speak English furthers their chances of improving their lifes. This is a short sighted view not uncommon for a people who see no need to travel beyond the province they live in for a career. It is unfortunate but a truism.
Now let me ask a question within the original question: how many of us thought when we were in school of living, working in a foreign country?
I know that even through my years of college earning my degree I had no inkling of living, working in any country but my own. My family was there, the language I was most familiar with was there -- spoken with different dialects of course but understandable by myself -- and my customs/culture was within the boudaries of my nation. Even while in the military visiting foreign countries I did not see myself living permanently outside of my native land. And I visited some interesting coutnries: Japan, Philippines, Germany and Thailand to name a few. My vision of the world at that time was not cosmopolitan but provincially focused on my own country.
So, let us not disparage the Thais for thinking, seeing of themselves in the same manner we grew up looking at the world.