To me personally, it’s a difference in the function of a room versus photos. Photos were always intended to capture memories, whereas a room was meant to be used and lived in. The idea of keeping the room as it was, permanently, feels like stagnation to me. I worry once it stopped being a comforting space, I still couldn’t bring myself to do anything with it because it would reopen the wound, so I’d just ignore it and live around it, and the feeling of stagnation would grow heavier.
But also everyone grieves differently, and I’ve never lost a child, so I can only guess how I’d grieve based on how I’ve grieved other relationships. It’s possible no one in that family feels the way I described. That’s just my best answer for why it sounds creepy to a bunch of us.