I'm wondering if this is simply a case of people feeling weird having a subordinate 10-20 years younger than themselves or bringing a 45 year old onto a team with a bunch of twenty-somethings.
Oh please. Older workers cost more (healthcare costs), won't put up with as much crap, and won't be in the workforce as long.
Also if you fire them, they can sue you based on Age Discrimination. Why do you think there's a law against discriminating against a person by age? Hmm, how did I ever get hired?
Adding manpower to a late software project makes it later. -- F. Brooks, "The Mythical Man-Month"