The frustrating thing is, Koji Igarashi didn't even make Castlevania.
Most early Castlevania games seem to have been made by various mixtures of Konami talent. Except for Super Castlevania, which was apparently made by Treasure, before they became Treasure.
The main producer on Dracula X for the PCE-CD and Symphony of the Night retired right after SotN was completed.
Koji Igarashi was brought in late in SotN's development to help "co-produce" the game. His main job was apparently to fight and try to convince Sony to ALLOW the game to even be made. He worked on the Japanese voice acting. He got credited with helping to write some of the "story" in SotN. And he did most of the PR work for the game.
Michiru Yamane didn't originally compose classics like Vampire Killer or Bloody Tears. Nobody seems to know or care who did. She did some okay remixes of them (like everyone else at Konami), along with some all-new tunes in "Castlevania: Bloodlines" on the Sega Genesis (which isn't the "Bloodlines" referred to at the beginning of SotN), . Then she did the wealth of new and diverse music in Symphony of the Night.
Ayami Kojima's first art in a Castlevania game was Symphony of the Night.
Then Koji Igarashi had an old Japan-only PC remake of Castlevania 1 ported to the PSX, and released in America (I'm not sure how he got that one past Sony). He "improved it" by including an art gallery by Ayami Kojima that had nothing to do with the PC remake of Castlevania 1. And he hinted that he wanted to port the PCE-CD version of Dracula X to the PSX. Yay Iga!
Konami decided that Koji Igarashi had real love for Castlevania, so they promoted him to being "in charge" of the entire Castlevania series. Yay Iga!
He "clarified" the Castlevania timeline. He made it make sense. Yay Iga!
And he wiped three games from the "official" Castlevania history, two of which were the most unpopular Castlevania games. Yay Iga?
Then he cancelled the Dreamcast Castlevania, which was being made in America by the producer of the Genesis Castlevania, which many people were worried was going to turn out as badly as the 3D N64 games (except that it would have CD audio). Yay Iga?
(In hindsight, I think it's clear that all four of his Castlevania eliminations were made because they were threats to his authority.)
Some Metroidvanias got made on the GBA. Iga wasn't really paying attention. Yay Iga.
Iga unveils Lament of Innocence on the PS2. It's mocked as a Devil May Cry clone, and yet, it's still as bad as the N64 games, except that it has CD audio. Boo Iga!
By now, Iga seems to have reduced Castlevania to "Symphony of the Night", while he still hasn't proven he can even match that game. His main concern seems to be bringing Castlevania into 3D, but he can't make an above-average 3D game, let alone one that's somehow suitable to be the next Castlevania.
The DS can handle a port of the SotN engine. They might actually put out something that's better than SotN. Yay Iga!
Oh wait, Castlevania DS can't have a dedicated artist, because Iga says Castlevania art must be "Ayami Kojima, or nothing". And she's busy working on Iga's next 3D bomb, so Castlevania DS will just have to do without unique artwork. Just "generic anime". They could've taken it up a notch, and used some real anime in the game, like Dracula X did, but Iga says no, and even if he didn't, he already blew all his money on that next 3D game. Good job Iga!