The order is an ancient group of beings that were here long before any humans of this age and will be here long after such humans are gone. They have done many things throughout their life on Earth but one thing they may never speak about is additives in food. Why? Because they like keeping humans complacent, docile, just plain dumb.
Why have humans that go against the status quo and make more work for them? They tried that and looked what happened, the dark ages. It took a lot of work for them to clean up that mess and they would rather amuse themselves other ways than to work at cleaning up human messes. So they gave humans what they needed, a brain sterilization.
The order let humans think they were being creative and helping with additives in foods, from coloring to fluoride, but in reality they have long been keeping humans dumbed down. Making them believe watching Justin Bieber concerts and reality TV was worth their time, instead of inventing and getting out in the world.
So now thanks to the order the humans remain stupid and slowly progress at things, not so stupid they are cavemen, but not so smart that they blow themselves up either. Thanks to the order humans can now prosper in their own sheer stupidity.