Because Korea is more developed, I would imagine. And Syria has state department advisories as a dangerous location for Americans to travel. Teaching English is a good way to travel abroad and not have it cost a lot, since they have guaranteed employment in their host country.
The program my daughter is on does all of the hard work in finding a place to live, arranging a vehicle, work visa, all of those complications for a young person living abroad.
I highly recommend it. It is remarkably easier these days, with Google maps for transportation. Public transit is amazing there. I’m fortunate that since my mother is Japanese, language isn’t much of a barrier for me, but I saw tons of folks using Google translate just fine. And the dollar is strong against the yen right now, so it’s a great time to go there!