From the (TOS) Star Trek writer’s/director’s guide, revised in 1967:
“The time is today. We’re in Viet Nam waters aboard the navy cruiser U.S.S. Detroit. Suddenly an enemy gunboat heads for us, our guns are unable to stop it, and we realize it’s a suicide attack with an atomic warhead. Total destruction of our vessel and of all aboard appears probable. Would Captain E. L. Henderson, presently commanding the U.S.S. Detroit, turn and hug a comely female WAVE who happened to be on the ship’s bridge.
As simple as that. This is our standard test that has led to STAR TREK believability. (It also suggests much of what has been wrong in filmed sf of the past.) No, Captain Henderson wouldn’t! Not if he’s the kind of Captain we hope is commanding any naval vessel of ours. Nor would our Captain Kirk hug a female crewman in a moment of danger, not if he’s to remain believable. (Some might prefer Henderson were somewhere making love rather than shelling Asiatic ports, but that’s a whole different story for a whole different network. Probably BBC.)”
I think the above has been a problem with Discovery from my perspective that's been evident since season 1 episode 1. When you predicate the protagonist’s motivations on emotional decisions, family ties, or interpersonal romance, it undermines the believability of their decision making and their believability as an officer/captain that the audience can trust. And it undermines the show.
In the current season, we have an anomaly that has destroyed entire planets, is spread across multiple light-years of the Milky Way, and is such a threat that most of the major powers have determined it to be a threat to galactic civilization. And yet, you would think the bigger threat we're supposed to be invested in is Book’s and Michael’s relationship by the importance the show gives to things and the actions of the characters.
1) There are multiple episodes where Kirk turns and hugs female crew members on the bridge during a crisis.
2) The scenario the TOS writers' bible outlines is absolutely not the same as writing characters as though their relationships matter, which is what you're complaining about.
3) It would be ridiculous and unrealistic for the characters not to make decisions in part on the basis of their feelings and relationships.