Because the media thought MJ was so weird and not normal, they treated him as an alien... They didn't think of him as a human with human experiences, so in their eyes, him having sex was completely unimaginable and just HAD to be made a big deal once they found out he said it himself. Plus the media just magnifies [& often twists] every single piece of info they get their hands on... It's just sad what the media does :/