I don't consider weed a drug because of the following:
If you look at people who smoke weed everyday, in general, they are lazy under achievers but they can still function in life. Albeit they may not be as high functioning as they could be, nonetheless they still function in life. If you look at someone who develops a bad drinking problem, coke problem, heroin problem etc they can't function in life. it destroys everything around them.
Unfortunately this just isn't true.
Marijuana has destroyed a lot more lives than it might first seem. Heavy use can induce severe paranoia and schizophrenia. Having "the munchies" is a subject that's easily amusing but for a lot of heavy users it will make you overweight which causes more problems. I have witnessed a bad weed problem destroy everything in someone's life. I've seen people turn to crime because of it and I've seen people go to rehab for it. You say in general but the problem is that you can't generalize because you're trivializing a serious problem. So, even if weed destroys the lives of 1% of the people that use it (a random figure) compared to say, 10% of heroin users... well that's still a fucking shitload of people. I mean, if you have a friend that is smoking a shitload of weed daily, he can barely function, he's paranoid, he's overweight, he's doing shady things for money to support his habit, and he comes to you for help, are you gonna stand there and say "man the fuck up you pussy, weed ain't even a drug"?
And also, coke is massively prevalent in corporate culture. When I used to work at the BBC, a lot of the execs, your typical business types in suits, people whose decisions and responsibilities are worth millions of pounds and can affect the lives of hundreds, sometimes thousands of staff, had serious coke problems. And they were more than able to function in life. It's the same in music. As I don't do coke myself, I tend not to associate with anyone in the music industry that does, but that doesn't matter to them, they'll just go and find someone else that does. There's a lot of bands that have been signed to a lot of labels over sharing a few lines with a label A&R in the bathroom of a club somewhere. Fashion too - when we played the MTV Style Awards a few years back which is a hybrid music and fashion event, a great deal of the models were on coke. A few of them asked me if I could hook them up with some. They are surely functioning in life.
I suppose what it boils down to is what you consider to be functioning. The coke addicts might not have great relationships in life. But the weedhead might not either, but likely for different reasons. The thing is that weed being much more prevalent means it also has it's own subculture. It's generally quite easy if you smoke weed to find a girl that likes smoking weed too, and to a lesser extent a job where it doesn't damage your ability to do your job. Examples - a friend of mine who smokes a lot of bud is a chef. It's easy for musicians to smoke bud because we have downtime in between shows, in between recording sessions, in between interviews. But, I have another friend who works in a bank and smokes weed. Of course, like most smokers he was lethargic, and he used to show up to work late because of it, and he got fired from at least one place for it. His judgement was clouded from smoking bud before he had to drive to different places, and he would regularly get into small incidents on the road that would add a few points to his license and of course ultimately got banned from driving for a year because of that, and lost another job because without being able to drive he couldn't get to the location. So he obviously was not properly functioning in life because of it.
My main point is just that there's way too many variables and every individual has a different experience, so you can't really make blanket claims about one thing not being a drug or being less serious than another because there's gonna be just as much evidence to contradict those arguments as there is to support them. Of course, with some things there's no doubt a higher risk of it affecting your life and I'm not trying to state otherwise.
You may not like the guy, but I think Sebastian has some pretty strong willpower and morals to have never touched a single drug. I don't know many people who I can say that about. That doesn't mean he should call anyone a moron for having done so either tho lol.