We have to remember that Judges are almost always former lawyers, often defence lawyers. A Judge is a person who sits in Judgement, and historically is expected to make wise decisions. 'Wisdom' to me is something that to me should involve common sense decision making, ideally producing beneficial outcomes. The people who make these 'judgements' are demonstrably not the people with the most wisdom amongst us, they are just people emerging from the legal fraternity who have gone through a series of hierachical steps to get where they are. These hierachical steps require political instincts.
The pool of Judges is a closed shop, it is off limits to many suitable people who may make wise decisions for the benefit of society. It is purely a receptacle for the kinds of human beings who become lawyers, and ultimately the ones who have the best political instincts. That's your answer when you ask 'why' this happened.
Therefore we should not be surprised when Judges make idiotic decisions, naively and stupidly releasing alleged murderers - murderers being people who unlawfully and wantonly kill other humans - out into the community with nothing more than an 'electronic bracelet' on their leg. How recently had the *alleged* killer *allegedly* killed? The memory of taking a persons life is still *allegedly* fresh in his psyche, the smell of their blood still *allegedly* lingering faintly in his nostrils - and he is put in a position where he can very easily abscond and take more lives. The police don't charge someone with murder without very strong grounds to do so.