As much as I agree with you about the silliness of the C-suite, the job of "head of risk" is an important position at a bank because they:
1. Keep people hired for their greed honest (in terms of creating their models), and
2. Keep track of "soft" risks that can't be tracked by models well and tail risk that is underpriced by models (ie keep track of the nebulous concept of "modeling risk").
In opposition to the rest of the senior executives - who encourage greed and actively ignorance of "soft" risks to make more money.
1. Keep people hired for their greed honest (in terms of creating their models), and
2. Keep track of "soft" risks that can't be tracked by models well and tail risk that is underpriced by models (ie keep track of the nebulous concept of "modeling risk").
In opposition to the rest of the senior executives - who encourage greed and actively ignorance of "soft" risks to make more money.