I concur with this. Trump being stupid, lazy, and unable to admit ever being wrong explains most of it. He also has a strong propensity for denial when he hears things he doesn’t like. He’s claimed that global warming isn’t happening, that sea level isn’t rising (or might rise one-eighth of an inch over the next 400 years), and in exactly the same vein, he claimed that COVID wasn’t a crisis and would just go away by itself in a few weeks.
Trump’s propensity for denial was further strengthened by the fact that even he knew that a real epidemic would have a big impact on the economy, thus undermining his popularity and weakening his re-election chances. So during the crucial months when drastic federal action should have been the top priority, Trump continued to deny that COVID was a problem and advised everyone else to do the same. That he was putting millions of people’s lives at risk probably never occurred to him, but if it did, he wouldn’t have cared.
ETA: That was supposed to be a reply to @Little_Nemo. I see what happened there – @puzzlegal was quoting them, and that’s what I replied to.