Why is Coronavirus the right virus to cause a global pandemic?
Short answer: because effective factors come together. They are:
Ease of transmission,
and Smart purpose — — Unlike Ebola, it doesn’t want to kill every single human. It just wants to kill enough and leave irreversible damage
This article is all looking at the spread of the Coronavirus from the lens of System Theory.
We live in dynamic systems. “Our world is filled with dynamic systems; all populations, human and otherwise, are dynamic systems, epidemics are dynamic systems, economies at all scales are dynamic systems. The more you look at the world around you, the more examples you see.” 
System Thinking is an effort to understand how dynamic systems operate. The goal behind System Theory is to improve our decision-making processes to adapt to the dynamic attributes of complex systems.
This is a complicated question that requires a multi-faceted answer. In this article, I’m going to answer it through the lens of System Theory.
Short answer: We’re slow at recognizing a change when is happening and slow at responding to it.
First, we need to be aware of our current mindset when approaching dynamic systems.