Painfully, painfully stupid comments here. If someone says X, and then goes on a rampage, that does not discredit X. Yes, the media wants you to believe that, unless it's Unabomber-style ramblings involved.
Grammar and style are both ultimately dictated by usage, so if someone insists on plugging in XYZ as a new ultra-PC pronoun I can't really prove that it is incorrect, no matter how ridiculous.
So, that said: The whole point of using "they" is when you don't know the gender of a person and don't want to presume by saying "he" or "she" or muddying up the text by saying "he or she". When you know the gender of a person, using the correct pronoun is better--it's both succinct and corresponds more closely with reality.
It's a touchy subject [I mean, some idiot flagged my comment--come on!] but people tend to over-correct in grammar quite a bit, and over-correcting with "they" happens like this.
You are rather elaborately saying that you want people who do what they're told and don't make waves. Got it--every manager wants that 100 percent. No kidding.
Style tip: When talking about a particular person, don't refer to him or her as "they".