A) In 38 states your conversations can be secretly recorded without your knowledge. Humanity has not crumbled under the weight.
A bit less privacy wouldn't cause society to crumble but would still be a bad thing. Ref: Soviet Union.
B) "Privacy does not stop at one individual". Correct, but it requires the consent of all of those people to maintain the privacy. You are trusting the other party to not repeat what you said, therefore you trust they won't use the recordings.
Yes, but also because it creates the inherent doubt of "my word against yours". Anyone can claim that something was said, a recording proves it with a much, much higher degree of reliability.
C) "You might tell someone something off-the-record in a conversation which you would never put in writing." Security via obscurity. If you don't want anyone to know you think it, don't write it or speak it.
...or just don't let them record it and tell them in person. Which is a tried and true technique used by people since, I would guess, writing was invented. What if I do want them to know what I think, but I don't want them to record it and republish it? Would it be ok with you if I am concerned about secret recording in that situation?
D) "What is the problem with simply telling someone you are going to record them?" Because in interactions with people with authority, they can use this to force you to stop doing so. See my original post. The right to record conversations you are a party to is a defensive one.
Since when is there a positive "right" to record conversations you are a party to? You seem to have a lust for entrapment - presumably you would enjoy living in a panopticon-type society where everyone records everyone else. Personally, I prefer a society where people can't covertly record one another in private interactions.
At the end of the day, the prohibition on 2nd party recording is to protect liars, cheats and thieves by removing the ability to accurately capture evidence of the conversation one was a party to and does nothing for privacy.
Yes, liars, cheats. Confiders. Penitants. Those seeking advice. Those seeking support. Those seeking comfort. Whistleblowers. People engaging in conduct which, while not wrong, would be judged by many. Those trying to show empathy or build camaraderie.
To be honest, your views on all this seem quite sociopathic to me. Human interaction is built on trust. Secret recording of conversations utterly destroys the scope for trust.
It is of course a totally different question as to whether police should be subject to secret or open recording. I happen to think that so long as they are acting as instruments of the state, they should be subject to recording. But private citizens should not without their informed consent.