Mike, I understand your feelings thinking that the sender is getting a raw deal. In reality as a sender, once a print has left the coop so to speak, it's out of your hands.
I don't worry too much once my prints have gone, someday you may be surprised and see or hear about one of your postcards that you have sent, you never know!
I helped one of my nieces when she was about eight years old, to make a postcard for her to send to her grandparents. When the last of those grandparents died, that postcard was found in the top drawer alongside the last grandparents bed. My niece has that postcard back in her possession about 13 years after it was sent.
Regarding sending postcards in an envelope, well that is a reasonable thing, but I prefer to receive a postcard with war wounds from the mailing system, they have their own character after that experience!