Changing the brush hardness using a mouse is counterintuitive.

There is a useful shortcut to adjust the brush size and hardness using a mouse. 'Control + Option + Click and drag right/left' adjusts the brush size, while 'Control + Option + Click and drag up/down' adjusts the brush hardness. Although the first shortcut works well, I find the second one unintuitive. For some reason, to increase ↑ the hardness, you need to drag the pointer down ↓, and to decrease it ↓, you need to drag up ↑. This behavior is confusing and unintuitive. I wonder if this was done on purpose or if it's some kind of bug. Can it be fixed somehow?