Looking at Steam's statements about softening their stance of what they'll allow... that I can remember at the moment, no video game ever produced is specifically known to be against the law for US citizens.
All but the shiftiest underground circles (who as it is take extreme measures to ensure people DON'T find them) tend to have some kinds of standards in how far they'll take underage content.
What other material or situation has a chance of rendering a game effectively banned nationwide from private possession, use, or trade, by an average person?
To clarify, that's 'banned' in the legislation sense. Since digital storefronts are run by companies who can choose what to sell.
Are people so disconnected and uneducated (thanks to constantly levelling down school programs) from basic republican or legal principles that they're up to a point that they question the basics. And because the SJWs have crossed the lines multiple time in censoring legal opinions, the question has been pushed back against it's initial common sense?
All games, movies, medias in general are submitted to the same basic regulation of a functioning society everywhere in the world: depending of it's scope (if nobody heard about it, nobody cares, but as soon as it is, it'll get scrutinised under the same regulation), everything that is illegal per the law as stated in Steam's guidelines:
Illegal content include (not exhaustive)
- Hate speech, i.e. speech that promotes hatred, violence or discrimination against groups of people based on ethnicity, religion, gender, age, disability or sexual orientation
- Pornography
- Adult content that isn't appropriately labeled and age-gated
- Libelous or defamatory statements
- Content you don't own or have adequate rights to
- Content that violates the laws of any jurisdiction in which it will be available
- Content that is patently offensive or intended to shock or disgust viewers
- Content that exploits children in any way
- Applications that modify customer's computers in unexpected or harmful ways, such as malware or viruses
- Applications that fraudulently attempts to gather sensitive information, such as Steam credentials or financial data (e.g. credit card information)
This is not just Steam guidelines, or anyone's, this is the actual laws. The only question regards:
- Content that is patently offensive or intended to shock or disgust viewers
This is such a loose definition, that it opened the door for both illegal content and uncalled censorship. For exemple, there is a strict difference between -depiction- of violence which is legal when labels/age-gating applies, and -promotion- of violence which is illegal. How do you distinct the two? That's the tricky part: unless Steam has a battery of legal and social experts that can accurately differentiate the two, it'll create a whole lot of mess if they start allowing content that is illegal and do nothing about it, because nobody likes to be targeted as an individual, a family or a group, and should they be sued, if Steam hosts content that is illegal they'll loose cases after cases...