Besides that, what difference does it make what gender is used in such a sentence? If one doesn't like "her" in that context then mentally switch to "him" while

Besides that, what difference does it make what gender is used in such a sentence? If one doesn't like "her" in that context then mentally switch to "him" while reading it. Why is it necessary to insist that the structure of a perfectly fine sentence be changed to suit someone's gender sensitivity?