Gender has replaced sex in English usage

Reader, Marianne Johnson, wrote: “I am quoting from my old grammar book. ‘Things may be of male or female sex, but only words can be of masculine, feminine, common, or neuter gender.’ I’d sure like to know if it is correct to use gender the way everyone uses it today.”
Both Marianne and I are about 50 years behind the times. I was also taught, and still believe, that gender refers to words.
In 1988, William Safire (1929-2009) declared, “At the Democratic Convention of 1984, sex disappeared.” He was referring to media reaction when Geraldine Ferraro was nominated for the U.S. vice-presidency. Headlines blared that she was, The First of Her Gender, to be so honoured.
Safire added, “Grammarians watching the theft of gender from their special lingo feel like mathematicians watching  parameter being ripped off to mean ‘limits.’”
Still, the OED notes that figuratively gender once did mean “sex.” By 1899, such usage was, “only jocular.”
Gender’s original meaning when borrowed into Middle English from Old French was, “kind; sort.” This meaning is now obsolete.
We can watch the way this word’s meaning has evolved if we look at Fowler. The first edition of Fowler’s Modern English Usage was published in 1902 by Oxford University Press. It contained no reference to gender. By 1983, Fowler had this to say: “gender, noun, is a grammatical term only. To talk of person or creatures of the masculine or feminine gender, meaning of the male or female sex, is either a jocularity or a blunder.”
When Oxford issued an updated edition in 2004, gender received full coverage. Fowler noted  that since the 1300s, gender has largely served in a grammatical capacity related to “groups of nouns in terms of their being masculine, feminine or neuter ... In modern English, grammatical gender exists only in the singular personal pronouns, he, she, it, his, hers, its, etc.”
Like other sources, Fowler believes gender’s  transformation is largely due to the feminist movement. Simply put, many women resent being classified according to their physical beings. Arguing that women are far more than a sum of their body parts, these feminists began to use gender rather than sex to identify who they were. This gender label was thought to denote what it is to be a woman.
The Stanford Encyclopedia of Philosophy (2008), following a 25-page discussion of this idea, has declared, “The jury is still out on the best, the most useful or the correct definition of what gender is.”
That may be, but 100 per cent of today’s younger generation and a similar number among media, always use gender rather than sex, even when it’s clear that sex is the required word. It hasn’t helped that English, unlike French and German, is a gender-neutral language.
All this gender-English has spawned several new compound expressions: gender gap, gender identity, gender role, gender-specific, for example.
Safire once wrote, “If you have a friend of the female sex, you are a red-blooded American boy, if you have a friend of the feminine gender, you have an unnatural attachment to a word.”