Reasoning under merging:
- These lists overlapped a lot
- Every genocide is democide anyway, so having second (genocide) list just for a subset of democides doesn't seem useful
- It seems more useful to have this information in one place
- Desync between these two lists would make a lot of mess, and many potential editors were unaware that there was a second list Taw
It is not true that every instance of a genocide is a democide! Mass sterilizations or removal of children can constitute genocide, but these are not democide because they don't involve any killings. Sure, the lists will overlap a fair bit, but they are quite distinct concepts. I think that having a list with both will only add to the common misunderstanding that genocides only involve killing, or that all killings are genocides.
I agree that distinct notions should be treated on separate pages. "Democide" refers to killing by government (the nature of the perpetrator is the basis for deciding whether or not something is a democide). "Genocide" refers to killing based on ethnicity (the nature of the victims is the basis here). I suspect that some genocides were perpetrated by groups without being ordered by governmental bodies, so wouldn't qualify as democides. Events should be classified carefully.