In my experience, a company holds to it's stated values because it has a strong central leader. A zealot if you will that's holdiy to them and inspiring others to stick with them. They are willing to risk it all because it's the right thing.
Most company's, values are extremely flexible depending on how profitable the company is. Companies with boards, shareholders, etc... First duty is to be profitable to them. If they can be profitable and good moral values that's great and many times it starts that way. When times get difficult it because values and morals go out the window.
The only value that matters to me: Do the right thing, as best as you can determine that, as best you can.