He's the President. When he downplays the seriousness of the virus, people listen. He quite a bit more time trying to talk up the economy than he did making the public aware of how serious the threat was. Based on what he was supposedly told by the experts, he should've been aggressively addressing the potential shortfalls in medical equipment in January or early February at the latest. He should've been pushing the public to start practicing containment measures around the same time instead of pushing a "business as usual" message to protect the economy. Once the experts started saying it was too late for containment, and we needed to look towards a strategy to mitigate the spread, he continued to push a message that the virus was contained.
I can continue for quite a while on the various ways that he totally botched the response to this.