in Castlevania's case, the showrunners talked about how Yoshiaki Kawajiri's movies were a big inspiration to what they wanted to do with the show, specifically stuff like Ninja Scroll and Vampire Hunter D
The problem is there's more to Kawajiri's work than just the sex and violence and knows how to get its story and characters across without relying on those aspects.
You see this problem in the studio's other shows as well. Seis Manos and Blood of Zeus have little to no substance except that they're violent and have sexual content. That's it. And there's a reason nobody talks about those shows even though the former came out last year and the latter was only a couple of months ago. The only thing that Castlevania has going for it is its name and that the animation is nice. If it was just "Generic Vampire Show" it would have been forgotten even quicker than it already has.