But in real life there are not transcripts of all daily conversations, and we survive fine without that. The preservation of all online conversations isn't necessary. Just look at some old archived USENET posts to discover how irrelevant they are, and this has only been amplified 10000% by everyone coming online and generating "content" through banal conversations about trivial things, pictures of their cat, food etc.
What’s the bar for “sensitive”? Anything that reveals something about yourself? This reply reveals that I’m more interested in privacy than many. Should or shouldn’t I be able to delete it?
I’ll concede that it may be rude, but given the trade-offs, I’m ok with being rude in this respect.