“No reason”? You already told us the reason: “impact” implies a certain physical effect. When it’s used to describe something non-physical, that effect carries over as a metaphor.
If I affect something, that effect might be soft or hard. If I impact something, it’s understood that that effect is solid.
Words have connotations, and using connotations deliberately is one of the marks of a good writer.
Please–obviously when I say “no reason” I mean in those cases when it has no reason to carry that particular connotation. In other words, just mechanically using it instead of affect nearly all the time, which is what has happened for a while now, so as to gradually leech away the original distinction. That benefit is pretty much sapped away, now. People on CNN say things like, “How does that impact the debate in Iran”, etc., just automatically, without any particular reason to apply that kind of metaphor–simply because it sounds more “journalistic,” or dramatic. It could be used to good effect, as you point out, if this weren’t the case, but instead by overuse it has become trite and worn out.
Sounds more like an advocate of E-Prime. (English from which all forms of the verb to be are forbidden.) Did he have any books by Korzybski on his shelf? But then albeit has the verb be in it, which means he was either contradicting himself or didn’t know vocabulary all that well.
Well, I hate to do this to such a good student, but I have to dock your grade, guizot, for this post for using “really” instead of “actually”. I know it’s a perfectly legitimate usage, but it annoys me. And apparently that’s all the reason I need.
He may have been advocating E-Prime but he never told us to write that way and he wrote “Passive voice!” next to every use of a form of the verb “to be” so he wasn’t completely clear on the concept. If he insisted that all papers be written in that style he should have told us upfront so I could have dropped the class immediately. I later had a boss who insisted that we never use the passive voice (in speech or writing) but at least he actually understood what the passive voice is.