A. Forget about changing people's behavior - focus on getting the organizational stuff right, or
B. Organizations don't/can't change so you have to focus on people's behavior to effectively make change happen.
So which is it? Probably not as simple as picking one or the other. Can we agree that people, process. tools and culture all play into "the change?" If you remember the book "Switch" by the Heath brothers, they talk about the "rider, the elephant, and the path." It's a great metaphor. The rider and elephant are our thoughts, beliefs and feelings about the change which are played out in our behavior. And the path is the environment around the change - the processes, tools and the culture/rules of the organization.
Trying to achieve individual behavior change in an enterprise-wide initiative is a huge challenge. But - shaping the path (the processes, the tools and the rules that people use) so that it is easier to "direct the elephant" is super effective. If you clear and shape the path to make it easier for people to do their jobs - you have a good chance of getting behavior change resulting in organizational resilience.
So my answer... focus on shaping the environment. It is way more within our control to work with and will ultimately impact behavior and organizational culture. That's my opinion - what's yours?