I've learned that a company's culture is based upon its lore. It's lore is the retelling of the times when the rules were bent to do the right thing.
Here's an example. I once inherited a small group of associates, one of whom was a "temp" who had been there for several years. Temporary personel don't receive health benefits, they don't get paid for holidays and they aren't accumulating a pension. Therefore, both parties should expect it to be a short term assignment. If the assignment lasts for years, then a situation is created where a group of people, "the temps", are compensated less equitably than their peers.
Soon after taking the assignment, I told my "temp" that I expected to gain some efficiencies by making several process improvements, and that within 3-6 months I would no longer need her services. When the time came to let her go, I did something unheard of. I gave her two weeks of severence pay. Not only that, I let the other associates know that I was trying to do the right thing by compensating a multi-year associate with a reasonable severance package.
By bending the rules in that manner, I created a story that was told for many years. I had added to the company's lore, which fed the culture that this is a company that cares about their people.
The moral of the story is that a company's culture is based upon the lore that is created when the rules are bent or broken. If a company's culture is to change, it must break some established rules.