Well, I disagree that it felt shallow or artificial. I followed it as a ramp up of military hostilities.
It's poor story telling, plain and simple. No sooner had they show us this thing than they immediately have a plan to destroy it and they go and destroy it. A plan which hinges of Finn having previous served aboard...which is entirely new information.
There's no ratcheting up of tension and stakes, it just comes entirely out on nowhere.
"We must find the map to Skywalker or we're all doomed...wait, nevermind FIRE THE DOOM LASER!"
The whole thing is one giant arse-pull. Add to that the way the destruction of the Republic (yes, I know it wasn't the whole Republic, but you'd be forgiven for thinking otherwise given the way it's presented) fell entirely flat because we're given no time to get to know any of it (and let's not even get into it being visible in the sky.) At least with Alderaan you had Leia's investment to latch onto. Hell, it was so perfunctory, many people (myself included) thought they'd just blown up Coruscant in what felt like an extremely offhand way.
I would be more inclined to say that the Rathtaar scene could be shortened or discarded to inform more about SKB. I think that scene was far more jarring than anything with SKB.
It's not mutually exclusive. Both were unnecessary; SKB is a storytelling problem that hobbles the entire third act.
The rathtaar sequence just screwed with the pacing in the second act so you have a frantic action sequence right after another frantic action sequence (the escape from Jakku) with barely a breath between them.
It's like the writers and/or director were afraid to have two characters speak to each other for more than two seconds without something blowing up in the background. That's a problem because it actually hurts the credibility of the relationship between Finn and Rey. Luckily the actors' chemistry saved it, but if you look at it structurally, there's no real reason those two should have become that attached to each other is such a short amount of time. They never really have much of a quiet moment to show they're connecting. It goes straight from Rey beating him up, to them both running for their lives, then the TIE chase, the coolant leak, the rathtaars and then straight to Takodana.
Unless the trip to Takodana takes a *long* time, in real terms they've know each other like 60 minutes topps before Finn splits.