Is that not the point of the rules lite? It fits within the theme and intent of the ability, after all. Or are you going to say that an evoker can't avoid destroying a wall with thieir fireball, but manage to avoid hitting a bag of rats in the dead center of the blast?
Its not a matter of house ruling, its a question of different understanding of the rules. The intent as I read it is that Scult Spell is that the wizard is shaping the spell so it doesn't damage people. "Making Saves" is just how the writers expressed the outcome. No one is actually trying to dodge the spell here - its the wizard just shaping the spell so that people just aren't being hit. Understandably, its expressed this way because so much of the game hyper focuses on combat, but the intent of the ability (Shaping blasts) has applications beyond just combat, which is why its so interesting of an ability to mess around with.I would rule that the evoker could allow up to four of the rats, assuming a third-level fireball, to automatically pass their saves and take no damage from the spell. Since there is no mention in the feature of objects, and since the rules on damaging objects make no mention of saving throws, and since the idea of a wall succeeding on a dexterity save strikes me as incongruous, I would say that the objects have failed their saves before the spell is even cast. Even the rats that survived the spell would still be in a flaming bag.
Of course, house rule as you like, but be clear that you are doing so.
How would you rate each second level tradition feature of the Wizard subclasses, on a scale from 1 to 10, and compared to a +2 ASI?
Arcane Ward
Minor Conjuration
Portent
Hypnotic Gaze
Sculpt Spells
Improved Minor Illusion
Grim Harvest
Minor Alchemy
Bladesong

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.