Man is so abysmally stupid that he continually attacks his saviors in the most loudmouthed and utterly unthinking manner, encouraged of course by the politicians and the politically controlled press.
This quotation from Concrete is actually referencing how modern medication is so often reviled when it in most instances heals and prolongs life. But it can certainly apply metaphorically to the inexplicable tendency of the population to support people and ideas which are actually against their best interests.
Locally in Austria Thomas Bernhard was called a Nestbeschmutzer: one who be-fowls his own nest or, in a different version, one who shits where he sleeps. Internationally, Thomas Bernhard is considered one of the most significant writers since WWII.
Thomas Bernhard spent most of his life under the cloud of tuberculosis and was always acutely aware that his life was fragile. I wonder what he would have said about the anti-vaxxers or the Fascist regime currently destroying America?