>>724535604 (OP)
Because SotN is first and foremost is Hagihara, not his assistant Igarashi.
Of Igarashi's games only HoD is atmospheric enough to somewhat resemble SotN, but even HoD is somewhat weaker (and, iirc, not exactly made by Igarashi either).
Igarashi's games aren't bad, they are good in their own way - but they are way too modern, bright and even lighthearted. Too many gimmicks, not enough dark and mysterious castles. Original Devil May Cry is more Castlevania than Aria-Dawn-Portraits-Bloodstained.