Yes, it is accurate to say that "statistically a new female hire in an IT shop is likely to be a designer, not a coder". It is factually accurate to say that, but is it right and moral and nice to say it?
Words can affect people, and set tone and expectations. Is it right for all us men to presume, unless shown otherwise, that the new female hire is not a coder? Will this help or hurt our industry? Every little teeny thing (like presuming this (which is a teeny thing)) can be detrimental and can build up. "Death by a thousand cuts", "Straw that broke the camel's back", our society recognises that sometimes lots of little things can be Too Much™ sometimes.
Would software/the company/society be a better place if we didn't vocalise these presumptions about women, especially if it reinforces negative stereotypes about them?
After all, we all know the mistakes that can come when a female starts getting bigger and we ask "Are you pregnant?". Manners say to be careful here, let's apply some manners, rather than fetishising statically accurate deductions, to presuming women aren't coders.
There's an old saying which appears to have been lost somewhere along the way:
"Offense can only be taken"
Live by it and you will never be offended. It is not the job of everybody around you to constantly walk on eggshells just to keep you happy. You are not at the center of the universe, after all.
I agree that there is a middle ground - when someone's quality of life is seriously suffering because, for example, someone is shouting abuse at them all day then something must be done. However, taking serious offence at people's ignorant opinions or ways of expression is unwise and in itself ignorant.
I'm anticipating prejudice so I shall address it pre-emptively - I am, in fact, a minority. In many places on this planet, I risk serious injury just for being what I am. People have expressed extremely ignorant opinions about the group I fall under in workplaces. I initially took offence upon hearing what I heard but then I moved past that stage and accepted that one cannot understand something they haven't dealt with directly. They were not trying to be mean, they merely did not understand because of their limited experience. How can I take offence when this is the case?
That's certainly a good sign that social sanctions for sexism, racism, etc work. People ~should~ think before they speak, much more than they do in most sites and blogs.
Suppose through a sequence of unfortunate events you find yourself needing to walk through a bad section of town. You have your choice of two roads. Down one road you see a group of 5 young men of a race that commits crimes significantly higher than average. Down the other road there's a group of 5 middle-aged women of a race that commits crimes less than average. Is it acceptable to be racist, sexist, and ageist in this scenario?
Asking a new employee from an 'ethnic minority' if he or she is the new cleaner is bad because being a cleaner is not perceived to be a 'good' job.
Asking a new female employee if she's a designer isn't so bad because, as far as I can tell, being a designer is no 'worse' than being a programmer.
Both examples could be considered something-ism, but I'd say the former is worth caring about, and the latter is a case of oversensitivity (potentially from both sides).
I generally try to err on the side of caution to keep from offending people, but I'm quite allergic to people that get offended too quickly.
(A special place in hell is reserved for people who get offended on behalf of other people.)