Memorials and funerals aren't for the dead. They are for the living. It gives us closure. It is a necessary part in processing the death of a loved one. Not everyone needs this to be part of their process of grief but many, if not most, do.
One day my mother or my sister will die. I will go to both their funeral/memorials. I won't listen to the indoctrination that the JWs insist on foisting on the bereaved. I also won't allow members of a religious group to control me. It isn't about them any more than it is about the dead. It is about me and what I need to process the death of people close to me. It sounds selfish, and to be honest... it should be. There is no reason to be selfless and thinking of others when processing your grief. That is the opposite of helpful.
What I need is to see their dead bodies. I need proof that they are dead. Once that is done I can go and finish processing elsewhere. No religious organization gets to control my right to grieve for people I was close to. Allowing them to have that control over me is a power that I refuse to give them.