I read some analysis on this in the guardian, it predicted this would happen, because the police have limited resources and can only follow up one of the two charges. This charge is chosen because there is far more likely to be incontrovertible evidence, probably in the form of paper trails etc. Whereas proving he raped children decades ago relies on witness testimony, which is far easier for his very expensive (taxpayer-funded, mind) lawyers to talk down in court.
If this cunt sees a single day in prison I call that a win.