Medical Marijuana Sales Are Increasing. So What's the Problem?

I just read this USA Today article, Booming medical pot sales concern officials, and there's something missing. I get that there's lots of marijuana being sold in California and that the cops don’t like it, but so what? The article never actually explains why any of this is a bad thing. If the author thinks I can figure that out for myself, he screwed up, because the whole thing sounds great to me.

The last line quotes a cop complaining about people who look "very healthy" buying marijuana. I'm still trying to figure out what the problem is. Healthy people are a sign that the medicine works and everything is going well. Quit spying on healthy people and go help someone in need. This is ridiculous.