I think this already sort of happens with Snapchat, though. And even Facebook, too. Really any app that allows you to see that the message has been read is really annoying to me. Lots of "you saw my message/snap, why didn't you reply to me?" happens. Maybe that's just a thing in my age-group, though. I don't take pictures on Snapchat because I don't like pictures of my face, weird as it sounds, and I don't think my life is interesting enough to take pictures/record it. It's weird to me that everything needs to be captured behind a screen. When I was on vacation, I had to coax my mom into putting the camera down for a bit, so that she could enjoy the moment with something other than a lens. Buuuut I guess I'm rambling, I'll stop now.Also, since you have to reply to unlock a message, by not doing so, you are sending another kind of message to the sender.
No, I am with you. I hate taking multiple pictures with the intention to document the moment as it disrupts the experience. If I want a record, I'll take one picture, then put my phone away. The return on investment drops precipitously with each successive photo.