Starting with the Aids scare, if you take the sheer amount of adult films made with no condoms, it would seem there is very, VERY little HIV cases involved.
In fact, most would argue its the lifestyle outside of the Adult industry that is far more dangerous, however, playing devils advocate. You could argue that the films help perpetuate the absence of condoms during intercourse.
But then, who the fuck are you to tell me what I should wear on my dick, so go fuck yourself and your condoms only rule!