The Thai government had and still have some problem with teachers local and foreigner (sex offender etc...) So now it is very hard to get a visa if you dont show all the documents that they ask for. Anyway people who have kids rather like to have their kids safe at school without any perverts around.
Sound good as so many people show up to Penang with hands in the pockets :) No documents except their passport. Looks like they are thinking about nothing when presenting them self at the embassy.