Why does somebody undertake a long-distance instructor course?

This is a hard one to answer because none of the answers really make any sense.
The most obvious answers are not very flattering:

1. Lazy
2. Stupid
3. Ignorant
4. Arrogant
5. No discipline
6. No credibility
7. No self-respect
8. Lacks the necessary competence
9. Likes the idea of being a tai chi instructor
10. Incapable of completing a genuine 'real world' instructor course in a known school

The sad part is that there are organisations out there profiteering from tai chi deadbeats.
This is why tai chi has no credibility in the 21st Century martial arts world.