I hate this sort of bait-and-switch politics used against progressive agendas. It's entirely intentional. There's a movement to legalize something and the opposition, in failing to prevent legalization, is successful in preventing a regulatory framework from being enacted alongside the rollout of legalization. So naturally the legalization creates far more problems than it needs to or should, and a few years later that same opposition wins an argument that legalization was a mistake and gets it undone.

This same exact story happened with drug decriminalization the Oregon several years ago. State republicans successfully muted discussion of accompanying drug treatment legislation, which if you've ever examined successful decriminalization programs like Portugal you know is at least 50% of a successful program. So decriminalization merely led to a worsening of addiction-related issues, and a few years later conservatives in state governments were successful in rolling back the whole program.

It's fucked. Thailand, don't let those who undermined your legalization efforts off the hook. Hold them accountable for the failure they intentionally engineered.