Avoiding sexism

Don’t be a sexist pig! (to quote an expression from the 1960s):

What’s wrong with this sentence? “A 24-hour manned gatehouse provides privacy and security for the successful community.”

Answer: It’s sexist. Don’t say “manned”; say “staffed.”

What’s wrong with this? “Sam has been a male nurse for 12 years.”

Answer: Eliminate “male.” If he’s a man, why state the obvious?