Can't agree that "message" art is inherently less excellent than any other, especially since all art contains messages of consonance or dissonance with the prevailing status quo :-) but more specifically, can't agree that reformist, progressive, or social justice message art is inherently inferior to "neutral" (i.e. uncritical?) art.
If Message Art -- such as contemporary movies or TV shows that consciously, include gay, female, or non-Anglo characters in an attempt to broaden audience appeal -- is inherently inferior, too close to propaganda to deserve a place in any serious canon, then...
... I guess we'll have to de-list the plays of GB Shaw, whose passionate socialist and proto-feminist beliefs informed his work throughout. And Dickens too, who made a conscious and self-righteous effort to draw attention to the lives of the poor and the social costs of inequity; and I suppose HB Stowe too, whose best-known work is a passionate critique of American slavery. Virginia Woolf will have to go, of course, with her heavy-handed feminist messaging, and Charlotte Perkins Gilman. All the anti-war poets are obviously far too "woke" in their critique of war profiteering and the immorality of war itself. Upton Sinclair will have to be added to the inferior woke-art list, and why not Sinclair Lewis too... and heck, I suppose Guess Who's Coming To Dinner must be a wholly inferior movie to, say, Birth of a Nation, because it consciously and "artificially" incorporates a positive Black character and highlights respectable bourgeois racism? Oh, and what about the original Star Trek, which made a conscious decision to place a Black female officer among the bridge crew? (pretty darn woke, back in its first season!)
Once a new idea has made it into the mainstream it stops being "weird" or contrived, and becomes part of an evolving social consensus. Network execs were very nervous about allowing Star Trek TOS to show American TV's first-ever interracial kiss, but Roddenberry and Co stuck to their guns on principle. They were being woke about it :-) does that make Star Trek TOS "propaganda"? Now it seems like no big deal, but back then interracial marriage had only been legal a few years in some States. It used to be that gay characters in film and fiction were invariably villains or at least despicable; the first few positive portrayals of gay characters made a lot of people feel uncomfortable and accuse writers/directors/etc. of "just making a statement" (in other words, being too woke). Now gay characters are no big deal for most viewers, though of course there are holdouts.
So I think what this author is complaining about is not so much artistic quality or lack of it, as the fact that the Overton Window is moving out of his comfort zone :-) I'm over 60 myself, and the window has moved far from where it was when I was young, on several axes. Some I deplore, others (like diversity in the casting of popular media) I find refreshing.
Seriously, what makes Dr Who or Star Trek retreads boring is not that they're trying to be a bit less exclusively Anglo-manly in their casting, trying to pass the Bechdel Test or at least broaden their market wider than AngloAmerican teen boys. What makes them boring is that they're retreads. Franchises just get tedious after a while (quite some time ago in these cases) ... and I think it's kinda funny that they only get called out as boring boilerplate work lacking in artistic merit (which they have been for years, imho) at the moment when they get more inclusive. The New Inclusivity imho is actually the only spark of interest in some TV and movie series which should have been wound up and retired years ago.