It is technically discrimination though, as the company would be treating unfit people differently than fit people on the average. I think that the word discrimination is unjustly given a sort of taboo meaning in that any actual discrimination is horrible. And yet nearly everything that we do relies on discriminating.
Indeed, it has a strong connotation, I guess I should have used unfair discrimination or bigoted discrimination or something... Although to avoid confusion, I prefer to use a different word for "legitimate differences", such as distinguish or differentiate.