That's true of the list in its current form because the security agencies have (or had) zero interest in making it otherwise and because they're largely insulat

That's true of the list in its current form because the security agencies have (or had) zero interest in making it otherwise and because they're largely insulated from public pressure. However, having realized that this inflexibility means it can't be used to effectively govern the travel of people with security clearances, there's a very good chance that the system that was perviously impervious to change will suddenly become very flexible - at least so far as development benefits the security agencies.