The old standard file permission system is the default on most unixy systems because it's easy to use and understand (more or less). That doesn't mean these systems don't have ACLs.
In Windows, it's there by default. I'm not claiming that windows is better or more secure, I am simply answering the question that was posed.
And that is exactly what makes it more secure than ACLs which are extremely complex and unwieldy to setup and manage.