It seems you just have a really hard time understanding functions. This isn't the first conversation that goes around and around in a circle. And this isn't something to debate, it's just how it works, TG or otherwise.
It doesn't seem like you tried it at all, because blue doesn't produce any "gray", it produces a solid white map fractal, because it's true blue. Seems you took a peek and formulated a opinion based in prejudice.
If you grab each channel, you have a solid map of that colour. If you combine all those maps back together as scalar, you have a solid map at 1.
I really suggest playing around with stuff. Experiment. And remember, no one is telling you to use it. Lol