Has it dawned on them (though I very much doubt it)?
Take for example a family, mother, father and 2 children in Malaysia or Cambodia or Laos or Myanmar. They wish to have a short holiday in Thailand and want to travel there by land, but that is going to cost them 1,200 BHT just to enter. With the introduction of this fee there will be a lot of people changing their plans and going elsewhere, or just holidaying in their own country.