Valve limited there store to "in general not contain products of a certain type (here AI art containing)".
But in case of Dolphin this isn't the case but a explicit ban of dolphine without it braking Valve TOS.
If Valve would but in their TOS that "emulators are generally not allowed" then rejecting Dolphine would be okay and no one would have wirten any blogs or news articles about it, or even tried to put it on steam.
Valve limited there store to "in general not contain products of a certain type (here AI art containing)".
But in case of Dolphin this isn't the case but a explicit ban of dolphine without it braking Valve TOS.
If Valve would but in their TOS that "emulators are generally not allowed" then rejecting Dolphine would be okay and no one would have wirten any blogs or news articles about it, or even tried to put it on steam.