Why no 'Backwards Strafe' option for Standard Type Movement?

[RyuSaarva]

if you wanna walk slower to avoid stuff, just lock on to the target and then you can walk slowly backwards.

[NessaWyvern]

if you wanna walk slower to avoid stuff, just lock on to the target and then you can walk slowly backwards.

He's trying to say that he doesn't want to walk slowly backwards. I use the same setup he does, standard camera with A and D replaced with strafe. It would be nice if I could also move backwards at the same speed, (you can't with standard) but after 6 or so years of playing, I have pretty much gotten used to the slight, quick wrist turn with my mouse, to turn sideways so I can stafe behind an AoE.