Personally... Photography, to most of the people, provides a means to allow us to remember a moment or object since we don't have dolphine memory. It provides a means to document an event, process, procedure and allow rthe spread of information.
Many people feels that the human body is the most beautiful creation by nature... thus, I guess Human images just ends up a majority of the image produced. Just look at ads... Human are the most common subject. Tho many of these may not be the most artistic... Human image also serve as a memory booster... Just look at the snappers with P&S... its the people that are caught in the image that matters, not the lamp post on the head or the distracting background, and P&S are designed to catch image of human subjects... not sun sets and sun rise... People can spend &800 on a P&S that will only take simple pictures, but that's enough... cos that's what they need... Something to remember with... And scantly clad? Just a bonus... Its often the most effective attention seeking technique... effective on both gender.
But... all these are due to the way we are brought up... we were brought up wearing clothes... everything underneath is a secret... something mysterious... And curiousity is the drive to gain knowledge. We humans are knowledge seekers, with perhaps the greatest amount of curiousity... and thus, anything revealing something not commonly seen, is attractive. Look at communities that are brought up with only pactical coverage... individuals in these communities are not interested in what's underneath... or rather they are more curious why we cover up so much.
Next, let's look at the law of nature. All living thing's ultimate aim is to mantain its own existence, and to reproduce to maintain the exitence of the species. Even the simplest living thing, bacteria (virus' classification as living is still in doubt) does only two things, feed to maintain its existence and reproduce (Virus does only one, reproduce). We humans, are also bound to these laws, the opposite gender induce interest as they are part of one of the ultimate aim, to reproduce. Being scantly clad is more suggestive, and thus interest us more. This interest developes once an individual reach the stage of maturation when reproduction is possible. So its just human nature. But, being humans, we are defiant. A small amount of individuals break away from this circle. But, back to the topic. Due to these, we are interested in the opposite gender, and with a tool such as photography that allow us to document. Such an interesting subject immediately becomes comething popular to document.
Perhaps if we were elephants... we'll feel that the elephat body or trunk is the most beautiful creation by nature. hee hee
My 2 cents