Rejoicing over the Death of an Evil Person

In 2013, when Margaret Thatcher died, some people celebrated her death--due to her destructive economic policies during her terms--not only in the UK but also in other places, like Chile. Rejoicing over her death was not only considered something unethical but a source of joy and happiness.  

Today I heard that Mujib Rahman Ansari, a senior Sunni extremist cleric and pro-Taliban, was killed in a blast. On social media platforms, many Afghanistanis expressed their happiness over his death. The first question that might come to our mind is, is this morally a good thing? This is not the right question. A more correct and accurate question to ask is whether the absence of someone who promoted and caused hatred, disgust, misery, and suffering brings us peace? 

I asked a friend of mine this question. He told me that "rejoicing over the death of an evil person should not only be considered normal but also morally justifiable. We humans naturally rejoice when we see that our suffering is over. Ethics and morality seem irrelevant when it comes to survival and to ending our suffering and continuing to live without misery."

I am still not convinced. Taking human life should not be justified in any circumstances, I think.