The critics are valid, the solutions are not (for activists, as it's it focus)
Conversations.im was (or is, haven't checked in a month) logs encrypted chats on cleartext by default, and history shows why that is a bad idea [0]
Until today I haven't seen a single XMPP that protects metadata, the roster is always on cleartext, to support omemo you are storing yet more info always, etc.
If the answer to Signal issues is XMPP, there is a lot of work to do before to even suggest going this path.
Conversations.im was (or is, haven't checked in a month) logs encrypted chats on cleartext by default, and history shows why that is a bad idea [0]
Until today I haven't seen a single XMPP that protects metadata, the roster is always on cleartext, to support omemo you are storing yet more info always, etc.
If the answer to Signal issues is XMPP, there is a lot of work to do before to even suggest going this path.
[0]: https://trac.adium.im/ticket/15722