Its illuminating that he is only interested in sexual crimes, as his criticism is one which can apply to all crimes ie its hardly only sexual crimes where there is a small percentile of false allegations and accusers remain unnamed while investigations go on.
I get the impression (and I may be wrong) that Stephen Fry is a very unhappy individual, suffering from a depressive illness, who does not perhaps view things in the same light as the consensus much of society chooses to live by. Which is fine as long as he doesn't meddle in the law, which is being enforced, not for his and his friends' benefit, but for the benefit of wider society.
The whole consensus behind Operation Yewtree is that past dubious practices are no longer acceptable and the excuses and authority that abusers hid behind in the past are no longer going to work. Obviously this will result in some dissention, but it doesn't mean it is wrong.
Its good that people are not afraid to express dissenting opinions, but Stephen Fry has led a privileged life which has been characterised by being forgiven for his many mistakes due to recognition of his talent. I think a little more self reflection on his own good fortune might give him some empathy for those who have suffered at the hands of abusers, but I doubt he has that sort of insight.