Who let the skitters out? Acorn and her stoneworking

[Prompt: A "negative" condition that has hidden advantages]
Oh, this is Acorn's whole story. Scattered Acorns was born to a family of gardeners, the power of plant cultivation and coaxing in their bones. It was a respectable occupation, one with middling but solid status. Oaks Island could always do with more green paws. When Red Squirrel announced he was carrying, the cohort eagerly anticipated their new little gardener.
So imagine what a claw to the face it was to find out Acorn was not a plant bender, but a rock one. Stoneworking was her magic. At little Acorn's touch, rock and bone would act like clay, bending to her will.
The thing was, the colonies didn't need a stone shaper. They already had cloudstone, which gave them access to light, strong rock they could manipulate without magic. Acorn's power was... redundant. Obsolete on arrival.
But Acorn would prove them wrong. While cloudstone was impressively useful, it had a lot of the same limitations as organic cells. Furthermore, access to the miracle mineral was limited to what stone floes they could fish out of the ocean. As such, cloudstone was used for armor, reinforcements, and rafts, but nothing large or long-lasting.
Regular rock, though -- now, that was abundant. And Acorn made use of it. She honed her powers in private, learning how to carve out stable, sizable shapes from masses of stone. She learned how to make modular stone sections, and press them together into unlimited configurations. Eventually, Acorn managed to stonework a massive and permanent bridge all the way to another island, something no other skitter had ever accomplished. With Acorn's infrastructure, two islands were functionally turned into one, and every skitter was able to access both islands for work and trade.
As the royals saw how the bridged islands thrived, they ordered the building of bridges between every major island of the colonies. With so much work ahead of her, Acorn had no choice but to found the Oakspines, thereby kicking off an voracious and unforeseeable period of expansion among the colonies. Acorn did for the colonies what roads did for the Roman Empire on Earth.
And it was all due to stonework: her obsolete, disappointing magic.