"preferred (but not required)" is what wikipedia actually says, along with generic-he being the current usage (not rule). Interestingly wikipedia also states "

"preferred (but not required)" is what wikipedia actually says, along with generic-he being the current usage (not rule). Interestingly wikipedia also states "In the 19th century, grammarians in England petitioned the British Parliament to declare gender-indeterminate pronouns as 'he' rather than 'they', which was common usage at the time. " The english language is far from a codified, logically consistent system.