Now Ms. Finnegan, I hate to pick a bone with you, but defining "true" successors of a game by what came before is at best a subjective term. It'd be like a Super Mario Purist saying that Mario64 and the subsequent 3D style Mario games not being true Mario games because of their more open-ish world approach to the game. It certainly isn't the same feeling playing M64 as playing say the titular SMB3. Both are essentially platformers, yes but in the same vein, Castlevania was a linear platformer as well and SOTN, while following the more open level design of Metroid, is still essentially a platformer with added RPG elements. It is still at heart a Castlevania Game, it comes directly after the previous game, is tied to the story of that game, and has returning characters from earlier entries of the more "traditional" Castlevania series (Alucard, Dracula, and the everpresent incarnation of Death).
Previously, though it doesn't have Dracula as the antagonist, Castlevania Bloodlines for the SEGA Genesis and Bloodlines X (which reintroduces Dracula as the antagonist) are the last "traditional" linear Castlevania entries, not Super Castlevania IV. Bloodlines X segues into the main story of SOTN.
So at heart it is still a Castlevania game. Just because the setup doesn't match the previous entries does not make it not a "true" Castlevania. I'd dare say that the Lords of Shadow series is less Castlevania than SOTN.
Also Simon's Quest was ambitious, though a lot of people didn't enjoy it, I loved it. It broke away from the linear aspect and made an interesting and (for me) fun quest through the post Castlevania I storyline. Castlevania III added in a wonderfully realized system of having "companions" to aid you in your quest to defeat Dracula as well as semi-non-linear paths to the endgame.
I'm of course very passionate about Castlevania, I grew up with the series as a staple, and found most of the entries (aside from the N64 games) to be mostly excellent executions of the theme, gameplay and all. Except for those damnable medusa heads. Fuck them.
The post SOTN "Metroidvania" entries are still great, they still carry the weight of the previous games (my personal post-SOTN favorite is Dawn of Sorrow).
Honestly ma'am, you're making the "no true Scotsman" argument, and that honestly is poor journalism even in an op-ed piece.