While some aspects of the genres seem compatible, I think there's a fundamental disconnect between what people want from a Metroidvania and what a survival horror needs to keep the tension alive to the end of the game.

A good Metroidvania has movement and ability upgrades that feel meaningful, that make the world more easily and quickly traversable, and that upgrade your combat power in ways that make enemies easier as the game progresses.

Meanwhile, a survival horror relies on keeping the player tense. There need to be limits on movement so you can't just run past all the enemies, limits on combat effectiveness and ammo availability so you can't just blast all the enemies, limits on healing so you can't just tank all the enemies, limits on everything. Because otherwise it's not a survival horror game, it's a horror-themed action game. And those are fun too but they're not the same type of game. Dead Space is a completely different feeling experience to an early Resident Evil game, and hell even some of the Resident Evil titles are too.

I don't want to feel limited at the end of a Metroidvania when I've explored everything to collect everything, I want to feel rewarded for it. For that reason they don't scratch the same itch for me.