I agree with all your points but this one. I think this may become common if Cannabis were legal in your area. I think it's only uncommon right now because people are using Cannabis in their own homes or someone else's home, for the most part.
The only thing alcohol and weed have in common is that they are both drugs. There is no overlap in the effects they have on me, except in the broadest sense: relaxation.
Alcohol makes you think there's nothing you can't accomplish. Weed makes you wonder how the hell you are gonna accomplish anything. And if you are too impaired to drive under weed, you damn well know it.
Driving while intoxicated is always a bad idea (hell, driving is usually a bad idea). But not all intoxicants leave you with the feeling that you can and should drive.
You can often tell who speaks from a place of complete and total ignorance on this subject, the (willfully) ignorant will try so very hard to equate driving shit-faced with driving on marijuana.
They couldn't be more different. Not a popular opinion, I know. It's also an ignorance-free point of view.
I'm not arguing for or against legalization (what I think you're responding to). I'm making an observation. OP described the number of accidents caused by cannabis users to be low or uncommon. I was replying that that's likely due to the (relatively) low number of cannabis users and users on the road, and proposed that, as it becomes legal, accidents (caused by cannabis use) will become more common.
I DID NOT say it would be equivalent to drunk driving accidents.
I DID NOT say driving stoned was the same as driving drunk.
I DID NOT say cannabis should remain illegal because of this.
Go ahead and call me ignorant, but at least read and reply to my comments instead of replying to things I never wrote.