Out of all politics, maybe libertarianism is the only one that is vaguely creative. The left wing is stuck for a century trying to force others to implement communism with no variation whatsoever. Even cuckservatives are at least somewhat pragmatic.
Obvious reasons why, trying to fulfill social needs without being able to wave your hands and say "WE'LL MAKE AN AGENCY FOR IT!" requires a lot of thinking and exploring hypotheticals. Making an agency for it requires creativity too, if you want the agency to
work, but neither left wingers or right wingers with statist views seem to care if anything works, they just want to have "an answer" and that's enough for one day.
Monarchists are pretty interesting/creative too, actually, even if monarchism is mostly a thought experiment at this point. To make a monarchy work, you need an entirely different set of hypotheticals than if you're a generic statist, since you can simply behead a monarch if he fucks up too visibly. As everyone should well realize by now, you can't actually behead a state without an even worse form of state replacing it.
My guess for the reason is the increasing prevalence of university degrees in the population causing a greater proportion of creatives to have gone through the relevant university courses (which are filled with indoctrination as we all know). It's the same reason why every journalist is leftist except for a small handful of righties who make that distinction their entire brand.
Leftism has preached that all actions, including art, should serve the purpose of social change, while there's far less moral imperative for conservatives & individualists to hawk their wares these days. Conservatives were much more open and vigorous in the early 20th century, enforcing moral and religious ideals, and that's the point- if you took a count of "leftists" in the 1930s, you'd be overwhelmingly underestimating leftist creativity, much like you'd underestimate right-wing creativity today. You have to consider not only the "quiet" partisans, but also the people who
would join a community of artists, but lose interest, based on the belief they are unwanted. Relevant university courses, indoctrination, and intellectualism are secondary because when academia was right-wing, there were still left-wing artists, and now that academia is left-wing, there are still right-wing artists. I would still expect a difference in frequency of art and medium used between left- and right-wingers based on average personality and temperament, but not nearly so stark a gap as the early 20th century or today.
Consider that idea with regard to your comments on journalism, by the way. Journalism wasn't always an overwhelmingly left-wing field. In fact, it wasn't even
mostly left-wing, until very recently indeed.
Also most of the media that inspired people to become creatives in the past few decades was leftist (i.e. Star Wars, Star Trek, Doctor Who, Hitchhiker's Guide, possibly Monty Python, &c. &c.), the only big exception being Lord of the Rings.
Your list is a bit brit-centric, but you may be missing the cart for the horse, many of these "leftist" examples are interpreted as being leftist when they tend to be individualistic and critical of government as a
rule, not in pursuit of socialism or total anarchy. If you siphon out libertarians and egoists in general from being classified as the "right-wing," then a significant chunk of creatives drain out with them, but right now that is where they do belong, just based on social dynamics.
On the authors of these "leftist" works: half of Monty Python's membership was "apolitical" yet somehow allegedly very active in their personal politics (wink wink, nudge nudge), and of the vocal ones Cleese is a liberal in the sense that there were once liberals in Britain and now there aren't. In America, he would likely be cast as "right-wing." Douglas Adams never weighed in on politics openly, but he frequently mocked Labour over the years. Not that comedy speaks explicitly to belief, of course, but he was hardly a leftist partisan. William Hartnell, the first Doctor in Doctor Who, was known Tory, as was much of the British TV space at the time (the US being the same, very conservative until the fellow travelers muscled in). Newman wasn't openly much of anything, but Wilson (key to the show's educational foundation) was vaguely conservative.
Much of the interest and premise that drove the early Star Trek was written by conservatives, who Roddenberry had to periodically chase off, because they were interrupting his Maoist fantasy- not so with the actors, quite a few were quiet Republicans. Likewise with Star Wars, Leigh Brackett (Empire Strikes Back) is one notable writer who was another individualist sort but contemporarily pro-war (Vietnam) and generally conservative, not unlike a great many other early sci-fi writers of her time.
