Several of those programs are scammy. I know people who’ve been screwed by their company in South Korea, Ethiopia, and the Philippines. I’m glad it worked for you, and it’s a worthwhile thing to try if it calls to you, but it’s a recipe for culture shock and depression if someone doesn’t fully understand and want that experience.
I’m an American living in Germany, and I teach German classes to new immigrants, so I see a lot of people who wanted something different, but didn’t specifically want Germany. It’s much more difficult for them to adjust to a new place than for people who specifically seek Germany out.
I also personally think teaching children is too important to leave to people who are untrained, even if they’re subject matter experts, but I may be biased as it’s my career. I definitely wouldn’t teach kindergarten, because I (like most people) don’t have the patience.