Well Filipinos voted for this President who was very clear on his policues and they got him and he is doing what he promised. Democracy right though perhaps not to everyone's taste. What is then the objection?
Edit: Additionally, extrajudicial executions are a sign that Duterte doesn't respect the law. If he continues to encourage vigilante killings, there is precedent for him to encourage law breaking in other areas. Who's not to say there won't be electoral laws being flouted?