The Color Mixer sliders are great, but they don't offer as much control as a series of curves when altering HSL. For example, if I wanted to target a range of hue between orange and red, I can't.
The screenshot below, from a video application, shows the type of curves that make these adjustments possible:

Just as with the Color Mixer sliders, I can take an input hue and rotate it. Unlike the Color Mixer sliders, I can decide the precise range of the input hue(s) and create a smooth adjustment.
Changing the Color Mixer sliders into curves would still give intuitive controls, but far more powerful.