The people who care.
The people who care think of an idea, an initiative and pursue an action. In a startup, people who care make or break the company culture. The values or ideals that the caring person or the caring group have will carryover and reflect in their initiatives and activities within the company.
Many employees want to be part of something bigger than themselves. When an employee cares about a topic or issue very deeply, they will take action and others with similar interests follow suit. But it always starts with the one who cares enough to do something about it. Great company cultures are rarely set by the majority of bystanders.
Great company cultures start and thrive on people who care about the topic or issue. If you want to build a great company culture, find the individuals who care and give them all the resources you can to let them implement ideas and initiatives and watch them grow. There will be challenges along the way but trusting the people who are leading the culture front and encouraging them would be the way to go to building a resilient company culture for the long term. The people who don’t care enough to do more than their roles and responsibilities will be there in each company. However, the company culture will be driven by the individuals who are passionate and voluntary lead the efforts.