Guess what? People I don't know in a porn video performing sexual acts as their profession in order to sexually arouse people watching them are "impersonal objects". So are male and female models who exist as clothing-racks or make-up canvases. Musicians and actors exist to entertain and their dignity and personality are not relevant. My garbageman is a guy who exists to make my cans of trash go away.
Even you, as highly as you must regard every human interaction in your every moment of existence, surely deal with a great number of people on a regular basis who exist simply to perform a function that you benefit from.
As for "you can essentially do what you will with them"... I think that speaks more to you than anyone who enjoys porn, strippers, pinup posters, musicians, dancers, actors, or anyone else that they have no personal regard for. That statement is kind of like a religious person finding out that I'm an atheist and incredulously responding with "if you don't believe in god, how come you're not out raping and murdering people?!".