I can understand why that's upsetting and would be open to a better way. If you read my other posts in this thread, and have a better idea of how to achieve the balance I've written about, i.e. a way of achieving that balance that would lower the psychological barrier and not involve doing wrong, I'd like to know what it is.
If the concern is about threads, why not at least allow deletion of comments that does not have answers?
I think in many cases instead of deleting, it would be nice to anonymize a comment, so it does not show the user name and does not show in the comments list of a profile either.