I am actually surprised that you report such widespread familiarity with this particularly easy-going and trouble-free bunch of meth users.  While I will not deny that there must be some like that, I still think there is something to the general claim that this stuff and the people who deal in it and use it regularly are usually quite troubled and can be dangerous.

As I have said before, I believe the only "solution" to the "drug problem" is across the board legalization. I think it is not only the most practical thing to do, but it is also the only moral thing to do. From a practical point of view, legalization will immediately disempower the criminal organizations which profit from inflated prices due to contraband laws. It will make drugs into something like alcohol, which, while still a public health problem, does not create the social problems and crime problems that drugs do, namely because it isn't illegal. Those who are addicted to it can obtain it at a reasonable price, and they do not have steal, or visit violence upon others to avoid arrest or detection.

Second, people have a moral right to access any substance they want, unless it can be directly used to bring violent harm to others (like explosives). Making some things illegal to consume is a real odd result in our society, and it is a real problem. There just isn't much logical or ethical support for that idea, although it has been present in American law and politics for a hundred years. Because of its longevity, it has simply been made "the norm" because nobody is old enough to remember that it wasn't always this way, and the world didn't end when there were no such laws.

These laws and the sentiments behind them are a product of the temperance mentality and the symbiotic relationship between that movement and racism and class politics at a particularly unique juncture in history. It got helped along by the medical profession, who had a direct interest in controlling what people could obtain to make themselves feel better, and creating the current situation where the only option for those who do not feel good is to purchase the highly overpriced (and largely unaffordable) services of physicians. In most cases, they don't feel any better afterwards. The physicians may have some scientific rationalization about their biochemistry, but that doesn't help them with their lives. Who it does help is the profession of medicine in general, who have a large population of people with nowhere else to go for help on whom to test their theories and learn what can be sold to the ruling class in the future. People have a right to choose whatever they want for health or medical purposes to make them feel better. If it kills them a little quicker, that is their choice. If the physicians don't like their biochemistry, then too bad. The physicians can throw away their records and worry about the biochemistry of those who want their services. The iatrogenic poverty associated with scientific medicine causes more deaths from stress now than they prevent with their partially effective interventions. The government has no business in that decision.