My mother in law is the same way, and I can’t say I disagree either. We are always saying “how could someone disregard their great grandparents that way?! Don’t they even care about where they came from?” Or in my case I assume sadly that they’ve gotten into drugs or something related to general societal decay. It’s a symptom.
But, on the upside, people are doing lovely things with old photos nowadays. Look around on Pinterest or etsy and you might be encouraged to donate them to a talented artist or crafter. They could at least make something dignified and beautiful with them. :)
Sadly, I have used those photos at antique centers for theater performers I have directed. And sometimes for comic effect. So I think I’ll probably be ripping them up - I’m afraid to put those old photos in the fireplace!!!