Regarding the porn issue I think the trend of hair removal, while having different connotations for some, was primarily to allow better viewing of the actual acts - just the next step in an industry that is required to go further and further.
On the issue of societal conditioning I think we are very much subject to it and I say this as a woman who does wear make-up and shaves her armpits.
My biggest concern though is, as it gradually becomes the culturally accepted norm to shave off pubes, there is the awful period for young teenagers when they really shouldn't have to be worrying about the faff of shaving their bits but are feeling pressurised by a generation of young men already very influenced by the images of hairless women in internet porn, to shave. This can be long before boyfriends and just down to jokes in the classroom or rumours from the changing rooms regarding their own bodies.
If as an adult women you feel you are making a choice it can feel empowering, but then again lots of pole-dancers will tell you the same about their choices and I would say must of us don't believe they are making their choices in a vacuum.
The bottom line is, do our 'choices' mean we are making it difficult, especially for the young, to choose not to shave. If we create an environment where words like 'unclean' and 'unhygienic' are regularly associated with full pubic hair, shaving becomes something that women no longer feel they have a real choice about. Also we pass this message back to our male partners and they are then likely to see those who don't shave as 'dirty'.
I hope women continue to feel like they have a choice as I really don't want it to be just another thing for my 3 daughters to worry and feel bad about, as they reach puberty. So in this sense it does matter what our motivations are. This choice ( the act of removing hair) could actually reduce the choices of others if we attach words like cleanliness and hygiene to it.