I’m genuinely surprised that you consider this an over-reaction. The banning of flights and closing of borders has been extremely limited. The majority of countries have targeted specific locations while they work out the severity of the newly identified strain. This seems like common sense to me. There already seems some evidence that this strain is more transimissable and more resistant to vaccines. If this is confirmed and it is also found to cause more severe covid then this is going to be a huge problem.