Ninefingers
Educated
My theory about righteous damage is that there is some cut content involving Cainhurst and the Vilebloods/Executioners storyline and it's a remnant of something we didn't get, much like the covenants which are clearly half assed and unfinished.
Righteous mainly affects the fuckers (except the goblin fucks AFAIK) in the castle and I wouldn't say that any of them are that hard to warrant a whole type of bonus damage just for them. But if there was more to that story than what we got, possibly involving more enemy types and some extra bosses then it would make sense.
That makes sense, Cainhurst does seem a bit rushed, the level itself is quite meh, the covenants are pointless - the only thing of interest is Alfred’s quest and Logarius.
The enemies inside are pretty uninspiring but those shitty things outside deserve to be righteously purged - so that’s one good use at least. Died way too many times to those fuckers.