If common understanding is such a good idea, then why doesn’t it happen more often inside companies?
Short answer: Because it’s hard to attain. Really hard.
But they’re considered nice words because we like having them. And we like having them because we know what the alternatives are, we know how hard they were to earn.
It’s not enough to know what a company thinks is a good thing, what a company likes.
You also need to know what the company is willing to fight tooth and nail for.