Let's get this into some kind of context...
I'm one of the people who "knew" what Jimmy Saville was like, because I was a photographer who had contact with his world. I "knew" that he liked 'em young, he never made any secret of the fact and nor did anyone else who was surrounded by groupies. Most of these young girls were legally old enough but nobody asked for proof of age...
These girls were the real predators, they would home in on anyone who they thought was famous, or anyone who worked with anyone famous, or who even knew anyone.
Did I report him? No, because
1. As far as I knew, he was doing nothing illegal. And I had no evidence anyway.
2. Nobody would have listened, including the police
3. It would have been incredibly stupid and dangerous to cause waves.
4. When young girls managed to get backstage they generally expected (and hoped for) 'some' degree of sexual activity. No doubt some were touched up or worse when they didn't expect or want it but it's difficult to blame the men involved, when the vast majority were keen to say the least.
4. Just about everyone in the entertainment/photography business at that time (60's and 70's) was the same. I knew a famous photographer (still alive) who expected to have sex with all his models. They were all old enough, AFAIK, and it was legal - but basically they had no choice, if they wanted him to photograph them then they knew what was expected of them and they accepted it.
The world has changed, mainly for the better. But Jimmy Saville, and the many others in a similar position at the same time, should really be judged by the standards of the day, not by the standards by which we now live.
As for what he did or didn't do at children's homes, that's different. But I'll tell you what does seem strange to me - some of these women allege that he assaulted them, not once, but many times, over a period of months or years. If their accounts are true, why did they go back for more?