I guess everybody is different.
When my ex-girlfriend and I broke up, we didn't stay friends either. We moved with our lives, each one to each side. As a photographer, I took lots of pictures of her, of us and of our trips together. The only photos I didn't erase are photos of me and photos of the places we visited. I don't want photos of her or us, and she didn't want photos of me either. Everything got to trash.
So yeah, I understand some people don't think that way and still want to keep memories of their exes, but when someone mentioned deleting the photos, those were not the target.
Plus, PLEASE stop talking about people passed away in this "why not delete the photos" topic. I was not the subject.