These phones go much farther the already absurd limitations of standard Android ("we know what apps a user doesn't care about so we'll kill them without asking, at any time").

Most developers are not aware of them, and in any case it's very hard to constantly save all the state

Hardly any previous system in the history of computers has ever required it, and Android's developer documentation doesn't highlight enough how much it's required.

Most of all it's the fault of these phones' extreme, undeclared, undocumented and absurd behavior anyhow.