Dangerous in the sense that it carries a hefty legal charge.
Take this example. What if they were to criminalize the manufacture and playing of guitars. If I start operating on the black market, selling guitars to my customers, does that make me an EVIL! person?
Pot dealers aren't bad people in the sense that they sell pot. They're providing a product to their target demographic and making a profit off of it. They're no worse than, say, the proprietors of a liquor store. They sell a mildly addicting product (there's little evidence for the claims that cannabis is addicting, but let's assume) to people who know what they're getting into and are fully responsible for their actions. There's nothing wrong with that at all.
I mean, if you're using it's illegal status as a reason to keep it illegal, I can't even begin to explain how stupid that sounds.
History has proven that illegalizing any kind of drug doesn't work. They repealed the Prohibition for good reasons, mainly because people were still getting alcohol anyways and it was costing them thousands to hunt distributors down. Yet another reason they repealed it was because the alcohol being made could either be completely clean or kill-you-in-a-minute toxic. In the end, making alcohol legal again was better for everyone's health and better for the government (yay taxes.) It keeps the crime out, the people drunk, and the government rich.
Wait... what does that remind you of? A drug that's illegal, that everyone gets anyways, and would benefit from legalization?