>>111695381More energy can go to brute force. They don't need much intelligence, anyways. Provided there's a superior to guide them they can be a threat.
I guess Homeworld's scraping for resources if they sent those idiots on a rescue mission. Then again, it was from the point of view of Homeworld just a 'find a big orange idiot who is probably busy beating local trees, wildlife and suspicious rock formations into pulp, mincemeat and dust accordingly' kinda mission, something even the rubies can manage.
If we go with my theory of Gem design and origin the stupidity was an intentional feature. The stupider a gem is, the more can it be trusted to fuse with other gems, as the risk of their programming breaking is minimal. There isn't that much of it there, after all.
That's why you don't see Sapphire fuse with other Sapphire: they're by default extremely smart. Better not risk that kinda intelligence going rebel because she discovered she has emotions.