I can only imagine how difficult it would be to come out and admit something like this as a victim. First off, you're a man and no man would ever want to admit being raped by another man. It is the most unmanly thing possible. Second, since it's a respectable celebrity, its going to be highly publicized. Most men have a hard time admitting something like this to their close friends/family, so imagine how much more difficult it would be to have the whole world know about it. Last, it's always the first person that has to be the most courageous. Once that happens, it's far less pressure for others to speak out knowing they are not alone.
Like the first dude said, it took him to reach 50 years of age to finally come to terms about what happened after decades of struggling.