It's not remotely true.
"Are you interested in Star Trek?"
"Not really, I just directed Wrath of Khan."
Meyer has written zero episodes of STD.
No, he was a consulting producer, which is a senior writing position.
In contrast, the first episode of Season 4 of STD was written by one Michelle Paradise, who has written seven episodes of STD. Her writing credits, of which there are 8 including STD, includes no science fiction. Meyer, when he got the job for STII, dove head-first into the available canon and lore and produced arguably the best of the Trek movies by actually giving a ᛋᚻᛁᛏ.
And the second episode of Season 4 was written by the writer of one of the best episodes of Battlestar Galactica. A quick perusal of other Discovery writers includes Joe Menowsky, who wrote "Darmok" and is an executive producer on BOTH Discovery and the Orville, superfan Akiva Goldsman, and a woman named after a TOS character.
Not to mention Jonathan Frakes is quite an odd choice in directors if you're trying to keep people connected from Star Trek (or Orville!) away from the show.
Most likely you're overestimating the individual writer's control in a show like this. They don't come up with the characters, plot, or story even if they have credits, just the details.
The ultimate problem with Star Trek is that there are 800+ episodes and however many movies. This is great if you're doing an animated comedy that relies on references but makes "serious" writing much more difficult since you're always treading the thin line between rehash and something too different.
Not even remotely true. Star Trek is an entire universe. Even halfway decent writers could produce a nearly infinite number of stories there.
Nobody cares about most of the Star Trek universe. It's just where the characters live, and these characters must act in a certain way for it to remain Star Trek. Both Discovery and Orville fail in this.
The writers of "Gunsmoke" seemed to do ok, having 635 episodes over twenty years.
The first few years written mostly by Meston were ok, by the end they were filing the serial numbers off his old radio shows. Dredd of course has varied wildly in quality, and at times has been almost literally unreadable.
"Boo hoo I have to color within the lines" is a complaint of *hack* writers, not good ones. Rules and constraints and limits are limits only on the talent of the writers.
The "lines" are dollars. Older Star Trek is Star Trek because of rules set by its budget. An episodic series with an ensemble cast and 22-26 episodes per season. Since you have a large number of episodes on a limited season budget, you get quite a few small-scale filler episodes that are really where Star Trek and its characters shine. If the story's bad you just move on, and a LOT of Star Trek is bad and always has been.
Discovery is completely different, it's run as a modern serialized prestige show. There are few episodes per season, each with a high budget. You need tight focus on the main plot, which is always epic and high-stakes. If the story's bad you're stuck with it unless you make awkward changes and drop plots mid-show.
The Klingons are fundamentally different; they simply are not the Klingons that had been *very* well defined.
Klingons gradually became a parody of themselves during and after TNG anyway.
When STD introduced the USS Enterprise, they not only changed the design, they made the thing thirty percent bigger, because of course they did.
They changed the design of the Enterprise??? I feel nauseous.
established canon that "there has never been a mutiny in Starfleet"
Spock actually said there was "absolutely no record of such an occurrence." No doubt he chose his words very carefully since he participated in two mutinies in the first season.
Discovery is probably bad but it's bad because the guy behind Hercules and Xena made a couple of billion dollars writing Transformers movies, ended up writing the Star Trek reboot, and naturally the worst US network brought him on to turn Star Trek into a "serious" prestige show so they'd have a flagship for their streaming service, not because someone's trying to destroy Star Trek. Most likely there are a lot of people who genuinely love Star Trek working on the show. They're beholden to people who are risk-averse and experienced at watered-down crap with broad appeal. Les Moonves, who really pushed Discovery before he got fired, could care less about Star Trek, being woke, or anything else besides massive amounts of money and he knew how to make it.
When I was a kid I had a book called The Nit-Picker's Guide to Star Trek or something but I always forget how seriously people take this stuff.