You raise an interesting point. It does seem dubious at best.
California's regulations have more weight than federal regulations at this point because manufacturers know if they want to sell in CA (they do) they need to comply.
You are forgetting. This is America. I have been experiencing intermittent anxiety, distress, and emotional angst over T2 illegal infringements of my rights. I personally value that distress at $100 per hour I cannot play GTA V with the mods I know and love. I imagine this exact feeling is shared by the 38,000 that have signed the petition. That is say, maybe half a million dollars in damages so far...
Not that is a very good legal argument (about on par with T2 assertions) but if I had a board room full of $800/hr lawyers you bet they could make that case on some level.