All the finger-pointing is pretty useless, but I think all of the parties mentioned above have done separate despicable things.
Agreed, sometimes there is TOO much depth into "why" someone is responsible for the death(s) of others. Sometimes it really has nothing to do with being protestant, jewish, catholic, christian, atheist, english, japanese, chinese, male, female, vampire, werewolf, or whatever other category they want to lump people into.
Sometimes people are just evil. There's no how or why to it, it's just how they are. And those people need to be dealt with accordingly, without putting a group label on them and looking for a group to blame.
As they said about 900 years ago in the Albigensian Crusade ... "Kill them all. God will know his own."