It's the Thursday before a holiday weekend and you've got a cost crisis. Someone in finance has just noticed that this month's AWS bill is trending 15% higher than last month's. An all-hands meeting is called, and everyone is asked to shut down as much capacity as they can "safely." All the work your team has been trying to push out before end of sprint is going to be delayed for days. Chances of an operational outage when someone shuts down something critical? Pretty high...
The impact of lost development time, lost customer feedback on new features, operational issues — these all pale before the long-term impact of making developers scared to develop and deploy.