

I don’t remember anything about all their designs being open source but they DID open source(*) the Roadster.
They also open sourced(*) their charging connector which has now become an increasingly used standard called NACS.
I’m putting that asterisks by open source because that’s only sorta-kinda what they did. More precisely they made the Roadster and TCC royalty free to use and released all of the engineering documents necessary to use & recreate them.
What you’re probably remembering is their Patent Pledge from 2014. At this point Tesla holds nearly 1,200 patents worldwide so that Patent Pledge isn’t a small thing. They’re surely not going to make all of their vehicle designs open source but they do seem to be holding to their Patent Pledge and its underlying “Open Innovation Framework”.
This doesn’t mean Musk or his companies are good, it’s just a review of the facts.
The EV1 was a wildly impractical vehicle with < 100 miles of range that cost $100,000 in 1996 money (over $200,000 today). It was never ever going to be any kind of mass produced consumer vehicle. Without GM subsidizing the ever loving shit out of them the only people who could have afforded them were the ultra wealthy.
Regardless, the only thing political was California’s insanely premature ZEV mandate set to take effect in 1998. That was political but not the EV1 itself.
BTW GM never really gave up on ZEV / PZEV even though most people think they did. I had a most excellent Hybrid Tahoe in the late 2000s but at 55k-ish new in 2009 ($82,000 today) it was simply too damn expensive to be a mass market vehicle. Just like the EV1.