At certain points in the history of Canadian public administration as I know it, government officials saw themselves as possessing their own legitimacy. I think that may have played a role.
On the other hand, I remember hearing politicians say that if we operated like the United States, everything would be fine. Look at how that turned out. When you centralize all authority and bring your cronies into all the top levels of the government, we know how that turns out.
I think we need to strike a balance. It's up to elected officials to make decisions. However, they shouldn't interfere in day-to-day management, or else things will clearly go off the rails.