Couldn’t part of the larger “why?” be that individual drivers are not sufficiently subject to liability for causing accidents with pedestrians, cyclists, etc.? If it is the case that it’s almost impossible for a driver to get in any trouble for causing such an accident (except in the most egregious cases of reckless driving) then it doesn’t make sense to avoid talking about that.
I can see value in not consistently talking about “btw killing someone with your car is basically a get out of jail card”. Most people probably don’t realize this.