Cryptographers don't have some sort of monopoly on what is right or what makes sense. Deniability is actually a good example of this. The idea of deniability as some sort of desirable feature in messaging came out of nowhere. It wasn't anything that anyone asked for or worried about before the OTR proposal suggested it. It is a cool idea but it has little practical value. That is particularly true when it depends on falsely claiming some sort of forgery when you know you actually said something embarrassing.