The government is not really a thinking body. Individuals think, but far less so when their livelihood, day to day operations and mode of achieving success requires very specific time scales. Our leaders are not scientifically literate, nor do they have experience with the entire range of possible threats. In most cases, their experience with biological threats has been rather low - many of them are raised in families and communities who don't just value public office, but have the resources to be able to think about pursuing occupations which aren't essential for basic survival. That is to say, they aren't food industry or infrastructure jobs - they are about governance, social commentary, social engineering, philosophical pursuit and management from a more abstracted, macro level.
To be able to think about these things, one must have sufficient resources to not be as concerned about basic survival, such as feeding onself. Thus, is it any surprise that some of them might overreact to a threat, especially given the pressure of consolidating an elevated need to avoid making mistakes, given the critical nature of the potential threat, with making decisions that have a high probability of falling within a range of normalcy. That it falls within a range of normalcy is important, as, given the murky outlook into such unfamiliar and grave events, the risk of inviting criticism is more pronounced than usual for any behaviour which falls too close to the edges of potential behaviours. If anyone decides to provide a heavily-weighted response to the threat, then they can immediately decry anyone with a lesser response as "not doing enough" for the benefit of those for whom they are accountable. This quickly escalates to a war of condemnation, and no politician is interested in allowing their reputation to suffer
For years, now, I've listened to rhetoric from intelligent individuals who denounce and condemn the corporations for infringing on privacy, all the while demanding that legislation is created and passed for the purpose of preserving and ensuring privacy rights for citizens. In doing so, they've also always been making the case that government oversight and power has to grow, to ensure that it has the means by which to administer "new rights" in the face of corporate monopolies, and technological change.