They have been told this, both politely and less so. It is no longer about them, it is about helping the public by warning that Cryptocat is dangerous snake oil being actively peddled as secure by incompetent developers who are not to be trusted with people's lives.
This will not be accomplished by merely providing the developers technical critiques. It will only be accomplished by informing the public in terms the public will understand. "Incompetent" is a suitable English word for that purpose.
> Shit, think of the chilling effect this even has on anyone out there who wants to try to build some security/crypto stuff.
Good!
> Myself I wouldn't even dare try
Very good!