Then obviously you shouldn't drive on marijuana. For the large majority of experienced smokers, there is no danger to it. You can find the studies for this. The only difference is the stoned driver goes a bit slower.
Why do they go a bit slower if there's no danger to it? Going slower implies that they're compensating for a delayed reaction time, in which case there is a danger.
Drunk drivers use the same arguments for why they're capable of driving under the influence. A lot of people think "well, it might be too difficult for some people, but I can handle it." Maybe they're right, but maybe not. Why not just avoid the issue altogether and not drive while you're high? I don't doubt for a second that drinking and driving or texting while driving are more dangerous, but that doesn't mean driving while you're high doesn't also possibly carry some risk.I haven't smoked much on the highway since then, but it was somewhat affirming. I knew I wasn't impaired, and if this wasn't the acid test for that situation I don't know what is.
So anyway, everyone's different. Know thy limitations. In my experience it's the occasional pot smoker, or non-smoker, who is aghast at the thought of driving on it. As perhaps they should be. But I smoke around twice a day. Cell phones and radios are more dangerous than the seasoned pot smoker on the road.
The kind of irresponsible nonchalance you have on the issue doesn't help the pro-legalization case.