For those who are interested about this development, you can read the news in Thai (and use google to translate it) here:

http://www.manager.co.th/business/vi...=9550000082200

The article basically talks about the fact the Bangkok - Samui route is being discontinued as it has become unprofitable as a result of the landing fees being increased by PG owned USM airport. With TG planes being full almost every flight, I don't see how a fee increase from about $3,000 to about $5,000/flight can cause TG to be unprofitable on this route.

In general, TG is not run by meritocracy but cronism and this explains a lot on how they could lose money on a route like BKK-Samui with flights that are mostly fully packed. If the landing fee is really the issue, I don't see a good logical reason why TG is not investing to build its own airport in Samui.