The burst of creativity is just marijuana (a medicinal drug) lifting your emotional hang ups so you express yourself with less restraints, more like a curious child. In other times it's not so pleasant but it's still the medicine freeing your anxieties up and out; but you need to face them, greet your biggest fears to see them out. It's why most people stop smoking, like a meditation journey, year by year it may get more terrifying observing your inner self, but facing anxieties is the only way to be rid of them. Weed accelerates the process if used with the right mind and ends, that is, to engage in self-therapy (e.g. playing and doing fun stuff). In psychoactive trips as with life, you have to take the good with the bad.
Perhaps it would work if I didn't have access to the internet and/or lived in a more nature-like area. Or perhaps it would work if my lifestyle was already different. I don't know. But as it is, if I smoke I become either couch-locked or jittery and paranoid.
I think individual differences matter a great deal, and you're right in pointing that out.
That said, the vast majority of regular pot smokers I know are more similar to me than they are to you, so based on that I think the negative bias is at least somewhat justified. I'd never tell someone not to smoke, I wouldn't judge chronic smokers no matter their lifestyle. But I've warned every one of my siblings and those curious about it to keep an eye out for how they respond to the stuff. It's nowhere near as potentially dangerous as alcohol, I think, but it's also not quite like picking up a coffee habit.
(I do have to confirm that I would occasionally get a burst of 'creativity' in particular when coding on purely-fun side-projects! Doing so was enjoyable and funny albeit not always very productive. I miss that sometimes.)