Adjust aperture just by turning the dial

[ReinisK]

I hope that I am not duplicating topics, but I couldn't find this.
So - what about changing the aperture just buy turning the dial?
In most situations we shoot with 1/50 and we don't need to change the shutter speed, but the need for changing the aperture is more often. So why not make it easier? The shutter speed could be adjusted by using the Av + dial, like it was with aperture.

[ReinisK]

Sorry, just looked in the not possible feature list, and looks like that this is one of them?