I've never smoked marijuana in my life and very likely never will. It's even legal in my state and I still don't smoke it.

The arguments in favor of legalization are many. We would save a lot of money currently going to prisons and police fighting the "drug war"; this money could go towards fixing roads and improving education. Legalizing and taxing marijuana creates a giant new revenue stream for local governments, again, which can be spent on bettering society.

And it absolutely is a freedom issue. It shouldn't be the government's role to tell people what kind of chemicals they can put in their body. If it has negative health consequences (All evidence points to the fact that it doesn't, by the way), then that's a decision for a person to make. Just like eating a double cheeseburger from McDonald's has negative effects and it's not the role of the government to tell you that you can't eat it, or drink a 2 liter of mountain dew, or smoke 5 packs of cigarettes every day, etc.

It does impair things like driving and operating equipment.

Yes and driving under the influence of marijuana would still be illegal, just like driving under the influence of any other drug is illegal. What makes you think it wouldn't be? This isn't even an argument.