It goes without saying that ESL is a worthwhile career; I myself make my living this way. To say "problem" is not the best way to begin this discussion. I do, however, notice many things that can change the idea of the field, in both the teachers who decide to do this, and the various countries and cultures in which they teach in.
I was once on a plane and overheard a native teacher from that country frustrated that many teachers treated their time as a break. Being involved in this field and having worked in various countries, I have met many teachers and aspiring travelers. I often ask many, why they are here, and why do they teach? To my dismay, I often receive the response, "I just wanted a gap year" or "I needed a break."
This idea that teaching in another country is an escape, could be damaging to the field. ESL teachers, whether rightly so or not, represent their countries. We all know that during a vacation, most of us are not as focused as we should be. Imagine that, but in the classroom.
Perhaps just as bad; not doing research. A surprising number of teachers who tell me "I need a break", often do not study up on where they are going. Perhaps these two mentalities come one after the other. If ESL teachers represent their culture, then their reactions to the culture represents them. It goes a long way to helping your teaching persona and experience in that country to do research about where you are going.
Finally, something that I myself have been guilty of, expecting more or less of a country. Some people travel to a country expecting a movie-type experience; others expecting a horrible one. Both ways of thinking damage the true experience you are having. I have met both ideas and have been surprised at some teachers' reasoning for this. The best way to refocus your attention is to realize that the experience you are having, is just that, sometimes a place cannot be explained with a simple clean answer. Your job as ESL teachers is to teach, represent your country's values and learn to adapt in the best way you can.
It is unfair to say that all ESL teachers who travel to another country are there for selfish motives, I do not believe this at all. But more and more, as ESL grows in the global community, it is important to understand our role and what effects it has on the industry and the people we serve. I see ESL and any teaching, whether of a foreign language or other subject, as important. Being able to represent yourself properly will go a long way to making your time as a teacher worthwhile and fun.