I think because that whole Finn/Rose story has some of the dumbest prequel-esque stuff in the entire film (BB-8 beating up prison guards with poker chips, BB-8 piloting an AT-ST) and also doesn’t really develop the characters of Finn/Rose. It’s a time sink in a 2.5 hour film.
In theory Finn’s arc is that he goes from only caring about Rey to being willing to sacrifice himself for the resistance, but quite how that self-sacrifice comes from learning that the entire Resistance/First Order conflict is just part of a larger military industrial complex is rather ???
There’s a lot of good, interesting ideas in the script (and in that sequence) but it really feels like it needed tightening / a second pair of eyes.
I guess the sequence also serves to set-up the coda with the stable boy, but I wasn’t fond of that either. Because the context is - the resistance has been whittled down to a handful of people, how will they continue the fight; the film’s answer = child soldiers?
Obviously I’m being flippant, I know the film wasn’t literally pro-child soldiers, but in the context of that planet’s storyline (focusing on the message that all conflict is a profit making enterprise) it’s another rather muddled theme. The Resistance is just part of a larger story in which the rich get richer and the poor are oppressed and sacrifice their lives for the conflict but yay the Jedi inspire people to join that conflict???