An organisation has personality of its own. To a large extent is it shaped by the personality of the CEO of organisation. Culture of Microsoft is not different from personality of Bill Gates or culture of Apple is not different from personality of Steve Jobs.
Personality of CEO also largely decides HR policies, it decides what kind of manpower gets hired, kind of behaviour that gets encouraged or discouraged, who gets promoted or fired, what gets discussed in reviews etc.
HR practitioner should be aware of this reality. In many cases HR practitioner tries to implement best practices from other organisation in their current organisation. Results are unpredictable- The initiative may succeed or just flops.
Even in same organisation, same initiative may succeed or fail in different periods of time.
Some practices can be generic ex. Respect for employees, transparency, recognition etc., while success of others largely depends on understanding the DNA of organisation i.e practices need to be specific.