The combination of the technology to synthesize these drugs from unconstrained pre-cursors, the intensity of their effect, the lack of education on the part of consumers, and a tracking/enforcement system which responds more slowly than conditions change is leading to a situation where tens of thousands of people are going to die essentially at their own hand.
It is not a question of 'people like to get high' it is that 'people getting high on arbitrary things will kill themselves'.
I understand that you're approaching this from a legalization standpoint, and on that we agree. But the overdose rate is "actually" sweeping the country now and that is born out by the available reports of emergency rooms around the country. And between your "regulated and safe" future and now, there is a large pile of unnecessarily dead people.