Regardless of a developer’s intentions with their product, we will not distribute content that appears, in our judgment, to depict sexual conduct involving a minor.

Steam doesn’t usually have a problem with gore.

day six featured a scene in which a man and his young daughter visit the farm. The daughter wants to ride one of the horses, resulting in an interactive dialogue sequence where the girl rides on the shoulders of a naked "horse" while it's led by the player.

I can see how this might’ve been interpreted as sexual.

Edit just in case: There’s a lot of shady shit Valve does that you could criticize. This is just blatant attention-seeking.