Gender issues

People often feel strongly about being gender-sensitive in writing (I'm strongly pro). But what about this?:

"Nearly everyone has opinions about modern questions even if their knowledge is as thin as of Greek science" -- Vallins (1951:76).'

Can the irredentists argue for "his"? "His or her" is ugly. Vallins says: "The construction […] is better avoided altogether" (ibid).

Then there's "Each of us has finished our work", "Each of us has finished his or her work".

Vallins, as always, is sensible here, even in 1951: "Most writers in order to do a great right do a little wrong, and write the sentence as […] 'Each of us have finished our work'. The plural of the personal pronouns knows no difference of sex; and it is wise to use it, if it is at all possible, instead of a more 'grammatically' correct he or she." (p.77) And you thought that gender sensitivity was invented by the feminists? As a footnote, I'd prefer: 'Each of us has finished their work.'

He's also good on "one": "The fact is, one is better avoided altogether, and we used as a convenient substitute." (p.77). But I can't resist David Crystal's made-up non-sexist quote that you can just imagine some county type saying: "One fell off one's horse" (p.106).

Crystal also notes two ungrammatical ways out of the gender trap that I defy almost anyone to criticise:

"Someone should be able to identify the author, shouldn't they?" (a school quizmaster), and "Anyone might have found it, mightn't they?" (an M.P.) (p.107).