LOOSE LIPS

In the US, it's because of an incredible complete bureaucracy.

You wouldn't believe how a seemingly simple action needs to first go through a number of departments to get approval.
These approvals take time, energy, and dedication in their consistency.

It's much easier for the bureaucrats in charge to do what they've already been doing in the past and not deal with the other bureaucrats in this bureaucratic system.

So they instead take the straightforward, but not optimal, way out and do what's best for them (or their dept) rather then what's best for the country and the people. Just my opinion anyways.