People-first language is about more than just being "politically correct". It is about addressing people as people. It is about not defining a person by their disability. My mother's favorite illustration of this is, "You wouldn't say, 'my grandmother is cancerous'." Of course you wouldn't. You would say, "My grandmother has cancer."
When people ask what I do for a living, I tell them I work in a group home for adults with disabilities. Note the subtle difference between saying someone is disabled and saying someone has a disability. A person is not his/her disability. I work in an ICFMR. By definition, all of the people who live there have been diagnosed with some level of mental retardation. I would never say, "A is mentally retarded." I would say, "A has moderate mental retardation." I would not say, "B is epileptic." I would say, "B has epilepsy."
All of the women I work with are unique individuals. Yes, each of them has half a page of diagnoses on her supportive information page, and each woman's list is different. But each of them differs in so many more important ways. A loves to throw things... so we bought her a foam dart set for her birthday. B is a girly-girl and got a mani-pedi for hers. C can never eat enough Cheetos. D recently discovered that she loves Zydeco music. E can spit watermelon seeds farther than anyone else I've ever known. F has lost most of her sight to a progressive disease, but has recently decided that she will learn to golf anyway. G loves her costume jewelry, and sometimes needs to be reminded not to wear it all at once. H collects pictures of puppies.
Each of these amazing women has an individual personality and her own likes, dislikes, hobbies, and interests. To define any one of them by her disabilities would be to forget that they are people first, and their disabilities are secondary to their personalities.