You can't fix stupid.
Stupidity is a chronic disorder. This strikes me as Ledger attempting to cater to the least common denominator, i.e. the really stupid! The trouble is that whenever you try to make something fool-proof, someone goes out and builds a better idiot. Maybe they're trying to compete with Jack Dorsey's (Block Inc) policy of "Shared-Self-Custody."
No matter how stupid it all sounds, this is still a positive thing. At least now we all know how unsafe it is and that there is a possibility of a backdoor, and this is a serious reason to completely abandon this product. Without this idiocy, many would still have full confidence in them.
How can we be sure that this seed phrase game is integrated only from firmware version 2.2.1? Have they already collected all the backups?