I agree with you guys but I also am not sure why it’s a priority to make it easy for users to tell other users why they should look at a topic. It isn’t that much work to copy the link into an email or message. I do this all day long and it’s fine.
That said, it would be nice if it were a bit easier. Maybe the right place for this would be in flag - eg. “Message someone else. This post contains something I want to tell another person directly and privately about. Does not cast a flag.”