Yeah, I’d also rather not have another planet-destroying weapon, especially when it’s so inconsequential to the actual plot. The other factor is that it’s not really “The First Order” that blows up Kijimi, it’s Palpatine. Palpatine’s behind it all.
But, hmm… I wonder if it were possible to edit it in such a way that the First Order kind of “bombs” the planet, but then cut away before the entire planet is destroyed. That could potentially be interesting; but I think I’d still rather just leave it out. There are enough explosions already.