Ern DSM:
The problem is if they were to ground all the 737-200 Adv out there, it would leave the low cost companies with a desperate shortage of machines to operate!
They are mostly old SAA airframes I believe, cheep to purchase but I would imagine rather expensive to operate, and the older they get, the more expensive they will get, I feel that sooner or later these low cost airlines will have to have a rethink, although I think Nationwide is in the process of upgrading to the 300?
There are also a few others using the 200, BA/Comair, Kalula etc.