EFF has criticized WhatsApp for being closed source, but not for this particular aspect of the key exchange functionality.
Because of the history around how WhatsApp was criticism over this and some of the apparent results of that criticism, tptacek particularly doesn't want people to conflate "there is something bad, unfortunate, or inadequate about WhatsApp" with "WhatsApp has a 'backdoor' in its key exchange" (and I understand that!).
> EFF has criticized WhatsApp for being closed source, but not for this particular aspect of the key exchange functionality.
The articles I've seen appeared carefully worded so as to achieve some balance, but did express some criticism and concern.
"Nevertheless, this is certainly a vulnerability of WhatsApp, and they should give users the choice to opt into more restrictive Signal-like defaults." from:
And the owner of the Signal protocol (which is what WhatsApp uses). Obviously he's not going to argue against it.