I get what you mean, but Dead Cells was already a completed roguelike on launch. The DLC’s add variety and additional story, but you can still get the full gameplay experience with just the base game.
It’s like saying you won’t support the Elden Ring because it has DLC.
Also, the Castlevania DLC is just fucking cool. The soundtrack for those levels alone are just -chef’s kiss-, and probably the closest we’ll get to a new 2D Castlevania 🥲