I can remember same or similar discussion has been in existence here but anyway this matter or discussion to some extent, we are not suppose to discuss it here because it is a matter of choice and personal decision I want to believe everyone knows to an extent what is suppose to be disclose and what is not suppose to be disclose. We are living in a strange world with strange people I use the word strange because we can't predict what will happen in the next minute and you can not also predict what some being are capable of doing. So anyone who feels it is good to share their private key fine and anyone who do not want to share fine even before signing up in..., they will tell you not to share this with anyone for your own safety and for your own good and I believe they are not stupid.
I understand this is a matter of privacy and personal choice, but I still agree with the OP, and this is worth an open discussion. Just like you have said, we can't predict what will happen in the next minute, which gives and brings a lot of questions concerning if what we are doing is right or wrong.
Coming public, like to engage in such discussion, will broaden the knowledge and understanding of many. What some might think is the best based on their own facts and ideas might actually need some adjustments. We are all learning every day, and learning never ends.