I didn't mean to gender, sorry if it was perceived that way. My understanding is that this is a standard industry term. Anyway, I'll try to use human years in the future.
"Man" is just Saxon/Old English for person (and is considered to be from at least PIE origins).
My late mum used to complain about the term Chair instead of Chairman, "I'm a person not a piece of furniture", she was chairman on lots of committees.