It's Valve's website, what they say goes. Pedophilia should not be tolerated in any way. Honestly Valve should have had it to where they track this games purchases and report them to authorities. That being said, depends on how much you want controlled and regulated or not.
Reading the character bios, it seems that this subject may only pertain to one character. The 25 year old teacher. Perhaps I'm mistaken, but if that's the case, and it is portrayed in a negative light, I wonder how this game differs from some other games in the industry. In Persona 5 for example, you are very early on in the game introduced to a character that targets younger school girls. But he is portrayed in a negative light, as a criminal.
However, the main difference I can see in this game is that the characters are significantly younger than the characters in Persona 5. They're around 10 years old here. And they're all girls, so that is suspicious.