We should not use people first language when talking about people with disabilities. Not only is it a very awkward way to speak and read, it places and emphasis that the person who you are speaking to is disabled. Disabled people want and need to be treated like normal members of society.
I do not think it is necessary to always use people-first language when discussing persons with disabilities. I don't think it is offensive to use language such as 'blind people' or 'disabled people.' Therefore, I see no need to convolute your sentence and twist your words around to become people-first.
While I applaud those would like to use inclusive and supportive language when referring to the disabled, I think it is possible to become so politically correct that the labels we use become awkward and further alienate the people that we are trying to protect.
I think if you want to support the disabled community, and I speak as the mother of a disabled child, be more careful of the words surrounding the label rather than the label itself. The problem of tone and using words such as 'retard' and others in a derogatory or mocking fashion is a far greater crime than whether or not you use people-first language.