Not necessarily. There are places where crime is low and so is police presence, like Taipei or Tokyo. It's part of culture which is actually adhered to by most.
If you go through Roppongi you'll see them, largely standing around. And in most shopping streets you'll see them patrolling on bicycles or in cars. They don't tend to stand around at malls or train stations, agreed, is that normal where you come from? (It wasn't the norm when I lived in the UK).