The number of stationary targets is so low, it's not worth neutering your ability to fight mobile foes. It does effectively no damage to enemies that can move (so, 99% of them), and the damage vs. a stationary target isn't phenomenal enough to bother with.
Even one major slow target, Kuzmann, barely takes any damage from it, and can only be held in place to nail him by using certain gimmicks like the glitched Overexposure card that will surely be fixed soon. He will still only take a few 10's worth of damage at most if he is walking around.