And that is the point of what they're saying. Being bored can be uncomfortable. One route out of that is to do something more interesting and productive, another is to alter your perception so that you are ok with it.
If people got to choose what they were doing it seems unlikely they would be bored in the first place though...
The stereotype of an absent-minded stoner is one way to look at it, but I often found that it caused my mind to wander and occasionally follow trains of thought that would normally be cut off earlier by "normal" thought processes.
That said, letting your mind wander can spur creativity and cannabis is something that enables this state. At the same time, if all you do is come up with random ideas (some of which might have value to yourself or others), it's only the start of the process. Brainstorming is great but if it never goes past the daydream phase, it may be irrelevant.
Either way, as I got older I stopped reacting positively to cannabis and I find it makes me more anxious than anything these days (yeah, yeah, I tried "that one strain I just had to try"). For whatever reason my brain just doesn't like being in that state anymore. But I'd never tell someone else how to relax or when it's valid to indulge in a bit of daydreaming if it agrees with them.
Banal: Overeating/overdrinking/overconsuming, sitting around, reading reddit/HN for hours, playing video games or twitch.
Not banal: Challenging yourself to new activities or hobbies that require skill. Seeing the world, interacting with other people IRL. Learning (new topics, reading, etc). Building things. Getting out of your comfort zone.
Essentially, being passive/not learning/not engaging vs. learning/challenging oneself and trying to be more than you are.
That said I can say that having depression (and a bit of PTSD) is way more of a hell without the weed to take my mind off it. And even if it's just playing a video game for 6 hours (rimworld is my current 2nd drug) that's far more active and engaging than my typical super depressed not leaving my bed state.
I also think bettering yourself and being a success isn't a one-size-fits-all package. I have a friend who smoked so much damn weed it's a wonder they have any brains left. They learned to play league of legends 10+ hours a day sometimes while high as a kite. They're now making multiple times the money streaming on twitch than they ever would've with any job they would be qualified for. They're the happiest they've ever been, met their SO through twitch, and are living the good life all by ignoring the advice being given here.
All those things feel AMAZING while high, even if the banal things feel way better than sober. Cannabis doesn't just somehow discriminate to make only unproductive activities feel better.
I personally reached the conclusion to start seriously self-learning coding while stoned out of my mind and would furiously code in my room while stoned out of my mind. Now, about seven years later, I have a good career as a developer and still get stoned silly every night.
We really need to look at society and ask why people are looking for a way out instead of a way in, but I guess it's easier to blame weed.
Some of the unhappiest people I know obsess over optimizing every second to be productive
We're not all Elon Musk, working 90 hours a week and always starting up a new start up. Banality will ensure we don't burn out before we're 40.
Also Bill Gates, Steve Jobs, Richard Feynman etc. (of course that doesn't prove anything - but it helps keeping things in proportion)
I would argue that striving for success is often the best way to actually not reach one's fullest potential.
That's basically what he said. You're doing something that you'd ordinarily find boring, but now you don't feel bored.
Feeling bored is your mind telling you that you should be doing something else.
Okay - so you normally would feel unpleasant. Now you don't because of weed. Of course you can argue weed is unhealthy - totally possible. But regarding the perceived state change. How is that causing harm? Because s/he's not going to become wealthy or "successful"?
The problem is if you do it to excess. When you would rather stay in and get high, than meet up with friends, drop out of school etc. When you are not living up to what you consider successful for yourself. Then you have a problem.
How do you define "boredom"?
According to Oxford Dictionary it means:
"Feeling weary and impatient because one is unoccupied or lacks interest in one's current activity." [1]
As far as my observations go this is particularly not fitting the perception experienced under the influence of weed.
Weed makes you feel - provided one responds positive to it - not weary, not impatient and one finds the present activity overly interesting.
> And it's when you're bored that you should be learning some new skill or discovering some new science or being creative. If you smoke pot you may grow up to find out that you aren't good at anything.
In my personal opinion I think that's alright. Not everybody has to be "good" at something. Whatever that even means.
[1]: https://en.oxforddictionaries.com/definition/bored
EDIT: I would like to mention that weed only makes me sleepy and helps relax. Also I don't think that one should respond to boredom (how I understand it) with weed - not at all. Drugs are never necessary to grow personally and often detrimental due to overuse.