I'm a designer and developer with 15+ years of professional experience and I would absolutely agree culture is more important than code.
I won't go as far to say as coding is easy, because it isn't. The effort it takes to create a platform is considerable. It's why we don't have that many options when it comes to social media.
But culture? That's HARD. Fostering an environment that's open and inclusive and limits abuse? That's so much more difficult.