I don't think the authorities really know what to do about this, so they just ignore it, and have their cake and eat it by officially saying it's illegal but effectively looking the other way because it is such a revenue generator that they dare not mess with. It not only acts a source of money for thousands of women and their improverished families, plus the money is spread over the whole country and local economies in the form of remittances, it draws in money for lots of other workers and industries that would suffer without it, such as restaurants, hotel, taxis, tours to all sorts of other services that tourists require. The caveat is that to make it legal is awkward for the international image of Thailand and future tourist perceptions (which they are clearly trying to manipulate to something different now), but also the practicallity of legalising it and giving adult industry workers the benefits and rights of other professions, whilst being a complete nightmare to tax or to even break even on it as it is notoriously a cash business and transactions are almost impossible to verify or track. Legalising it would end up costing the government far more than it could ever hope to bring in from it... so the easy answer is to just leave it as is. The idea of decriminalizing the trade sounds sensible and noble (and I'm not saying either side is correct), but the logistics and effects of doing so are far more complicated than most think, along with the potential disruption, unforseen results, and cost to the taxpayer it might cause... personally, I just don't think the governments wants to grasp this nettle and has more urgent issues to try to fix. After legalising cannabis and the mess that made with the U-turns etc., I doubt there is much appetite for such lofty crusading and grand changes at the moment... and importantly too, it might not be a vote winner as the there could be a backlash from the predictable sections of society.
