Earlier quoted context omitted.
These are possibilities but I think you missed a much more likely one -- they're just bullies who like to pick on people.
That falls under the "feeling superior" bucket. And like others have said it doesn't explain bias towards certain people.
Then, the people to whom the actual task of implementing it was left can’t deliver the grandiose perfectionist idea, and the narcissistic boss can and actually wants to fiercely abuse their power over them in order to feed on the high of superiority and control over them. It’s the perfect position for this kind of person, they can feel high all the time (eventually the tolerance will kick in and the boss must leave though but this can take some time).
Organization-wise it’s a bad boss really. It’s the job of the creatives to come up with great ideas, then the boss should moderate that working together with the feedback from the implementers. Instead the boss is due to personal weakness too suggestible against the creatives and puts the damage of his own making on to the team with bullying.