And their back up system is even weirder. They use two steel plates, one acting as a decryption key for the other. So if you lose one, you've lost your coins.
That sounds like a single point of failure to me 
Yeah, but no one is obliged to acquire the whole set that includes those two steel plates. User is free to buy only single hardware wallet ( too expensive for me though) and use the well-behaved method of storing SEED phrase on stainless washers as following all recommendations described in this threat.
