First of all, thank you to @Bokarda for initiating this idea with his Bohrok idea.
My pitch, however, is far different.
This idea is supposed to add a more comedic aspect to the world of Brickonicle, as I have noticed that there has been a distinct lack of LEGO humor so far. (barring Vohrahk's disturbing eating.) For a reference to wear I'm going with this, think of the Bots in Nexo Knights; idiotic robot midgets, built for simple jobs like maintenance.
Built by this universes Nuparu (mirroring the fact that he built the weapons made from the Bohrok is G1), the Bohrok were built to be simple, subservient drones meant to make the lives of Matoran easier. (For another point of reference, think House Elves from Harry Potter) Due to high demand, the Bohrok have been customized, a color chosen for each region. The Bohrok have low-level AI, able to make simple decisions for themselves. They are also able to express themselves, by colored pixelized expressions, each color different for every type of Bohrok. As you can probably tell, they are meant for comic relief purposes, but that doesn't mean they can't have story significance.
My idea is that by the time the story starts, the Bohrok have come into household use already and are being mass-produced by the thousands. Some have been reprogrammed to be spies and messengers for the Brotherhood of Makuta. (You can tell which Bohrok have been reprogrammed by the color of their eyes; if they turn pitch black, it's been turned.) Some have also been upgraded for low-level combat situations, such as when you need an expendable army. Also, perhaps in the second year, they are weaponized with a virus called the 'KRANA', and set against the Toa by the Brotherhood to further hinder their abilities. But their main use will always have been housekeeping, always chanting 'CLEAN IT ALL. IT MUST BE CLEANED.' The picture above expresses that, in a humorous way.
What he said.
As always, C&C are welcome, and I will see you next time!