Isn't it annoying if you cannot transfer data from your Internet computer to your offline computer? And what's about cloud services?
If a "security" measure is causing disruption to the business, it's not doing its job.
I don't think there's any spectrum here. Good security is what helps the company's business goals. Bad security (which isn't really security) hurts it. Sometimes there are legitimate questions about whether to optimize for short-term or long-term goals, but that's no different for every other business decision a company makes.
That normally covers all high security work, but 99% of the work of a government is communicating with the public, on both directions.
Plus how will government internet services be able to access data on the Intranet and vice versa.
I suspect at some point the will end up with computers connected to both networks and those will need to be constantly monitored and kept secure.
At the end of the day if they offer any internet based services to their citizens that data needs to make its way back to the Intranet somehow.
If service is required for work - it should on corporate network.