Common sense? Take the signal protocol. Theres more innocent people using it for whatever purpose than there are guilty people using it for whatever purpose. You can’t not develop or use a technology just because somebody else might use it for nefarious purposes. Bad people do bad things on the normal internet, does that mean we should start restricting internet usage because someone might do something bad? Of course not, thats just stupid. So why doesn’t the same hold true for encryption technologies? Sure someone with ill intentions is going to do things with it we don’t like, but the majority of users are just wanting to use said technology so governments and corporations don’t see what they are doing.
Or are we not entitled to privacy simply because some people use their privacy to harm others?