It's because he's responsible for Austin energy. All the other power companies didn't have as many outages. And while that can be blamed on nature, a week later a large portion with Austin energy still had no power. This is after several water quality problems. Police problems. And so on.

The position of city manager is a municipal position, not a state position. Cronk was a municipal official, and his "boss" was the Austin City Council, which is nominally nonpartisan but has a 10-to-1 Democrat-to-Republican composition out of eleven members. The City Council selected him to manage Austin as its "chief executive officer." He faced consequences because 9 out of 10 Democrats on the City Council and the lone Republican decided together that he could no longer meet the needs of the job after this latest fiasco. He was fired by the same Democrats that also run the city and were elected in municipal elections (unlike him, who was selected by elected officials but himself faces no municipal election). A proposal (2021 Prop F) to replace the council-manager system in Austin with a mayor-council system lost by 70 percentage points.

Just a week ago, Cronk announced that he had negotiated a four-year contract with Austin's police union despite the City Council wanting a one-year contract so that they could figure out reforms and public proposals as well. This very public disagreement (which was no doubt embarrassing to the City Council) coupled with public outrage over the management of Austin Energy made it a very easy decision to sack Cronk now.