To upload a game to Steam, you have to (except giving them $100) sign an “NDA” (non-disclosure agreement = don’t spread any secret information we give to you), and when you’ve signed that, you also have to sign their “SDA” (“Steam Distribution Agreement” = probably containing rules about how you’re allowed to distribute your game and not). This creates the following situation:
1. You have to sign Steam’s NDA to read what’s in Steam’s SDA.
2. By signing Steam’s NDA, you agree on not talking about what’s in Steam’s SDA.
Which equals: No one can ever talk about what’s in Steam’s SDA.
So if Steam wanted to put some weird-ass rules in their SDA it wouldn’t be a problem to them, because even if it’s weird-ass enough for game developers to complain about it and tell their friends about their weird-ass agreements with Steam, by doing so these game developers will break the NDA and maybe get in trouble.
I’m not saying that Steam’s SDA contains weird-ass agreement terms, because I don’t know (because I haven’t signed the NDA giving me access to the SDA), I’m just saying that if they wanted to put weird-ass agreement terms in their SDA they could, and no one would talk about it, because no one can’t.