I have a different explanation. Like many corrupt Asian governments (and I have lived in Asia for 10y+) they usually abide to this principle: if you discover some new way to make money, we either have to make money too out of it and without doing anything, or you have to stop. So in this case my theory is that they looked at it and like most computer illiterate governments they thought to stop it until they understand how the game works and start making money out of it themselves. I mean personally. Expect pretty soon to see some new Bitcoin service to appear in Thailand, with some weird license from the government, and founded (probably indirectly) by some corrupted member of the government or someone from their relatives.