Ian - I'm new to APUG, (like as of today!) but very interesting article. Like all good treatises(?) it possibly asks more questions than it answers - and that's good! I think that the questions you pose pertain to all art forms and subjects and that your article is as valid to the landscape photographer as it is to the nude photographer.
All art should generate an emotional response in the viewer and ideally that response should in some ways mirror that of the artist and so the subject matter is immaterial. We're just sharing our own emotions. Whenever I'm asked to write an "Artist's Statement" I inevitably suggest that we photograph not subjects or objects, but emotions. Our task as artist is to convey some of that emotion to our viewers.
We all hit periods where we question why we do what we do, and when we open ourselves to comment on such very personal issues as this we run the risk, (as you've seen) of hearing from those who KNOW, not just believe like the rest of us. Listen only to those you respect and discard the rest. Here's a hint though, when someone uses "University Professor" as a pejorative you may just want to switch off!
Clearly you respond to the nude figure - as we all do if we're honest - and seek to convey that tenderness and intimacy in your work. Good for you! Keep at it - but don't expect to fully understand it. Art is for expressing what the limitations of language cannot.