The reason they didn't is likely is that to make it veer randomly is likely they'd have likely actually need to redo how flinch itself works. While it shouldn't be overall to much work, but the level of repercussion could be quite severe on the gameplay. It could be a risk not worth venturing. From their point of view. Either way, they should implement something like what Blizzard has for overwatch. Have a playlist that has a beta of a patch to see how well it's received before it goes live, in case something needs more tweekimg.