And here I thought Apple had actually made an effort to make the key hard to backup (like how all NFC technologies nowadays incorporate "secure elements" in too-much-trouble-to-read chips). Seems it was all just bogus and Apple sucked as much as one would've expected.

@mikael I'll have to retract my statement previously regarding how they store the key after reading the above article and this claim that the encryption key is just simply stored in the NAND flash:
"So the file system key (which the FBI claims it is scared will be destroyed by the phone’s auto-erase security protection) is stored in the Effaceable Storage on the iPhone in the “NAND” flash memory."

My apparently false statement (see how I safeguarded with an "afaik" clause!): https://social.umeahackerspace.se/notice/399603