Basically all people hate being lied to, or to feel manipulated or controlled.
A lot of people on the anti-mask train were totally on board for the '2 week lockdown' to flatten the curve. Those same people then saw their government officials repeatedly lie to them ("masks don't work!" ~ "Herd Immunity @ X%", etc), the media painted the picture of airborne ebola, and then those same politicians went out and violated their own lockdown orders.
Meanwhile, their local economy is destroyed and they or people they care about are suffering/struggling. And for those that take a more global view of things, there is some [0,1]evidence that supply chain disruption is killing more people than Covid itself.
It's easy to feel like those people are complete idiots and ruining it for everyone else. It's much harder, but much more valuable, to focus on solutions to the underlying problem. Ultimately, we need to restore trust in our institutions before we can begin to repair the divide.
[0]https://time.com/5864803/oxfam-hunger-covid-19/ [1]https://www.un.org/press/en/2020/ga12294.doc.htm