It makes sense to me.
It's not exactly the art direction. The closer it looks to anime, the more it stands out to have a character just standing there. The idea of the MC being an stand in for the player is that the player feels free to feel and react however they feel appropriate to a situation. Even if the character doesn't speak (which is weird on itself), the fact that their face stays emotionless when the rest are beautifully animated for sure stands out.