I don't get it. I don't want to minimize someone else's grief, or dictate how they remember their beloved dead, but I don't know why marking the death site is so important. (My mother died in a hospital, my father in a nursing home; I wouldn't want to mark either site.) For that matter, it seems to me that appropriating a public right of way for a private memorial is some kind of imposition upon one's fellow citizens. Do we owe them a reverence? Or do they owe us an uncluttered street? I am unsure of what pietas would demand.
I also note that graves are becoming more cluttered these days. I've never been a biggie for visiting graves or decorating them, but I understand that that's important to many people. But recently, I've notice that some graves are just filled with ceramic dolls, religious statues, floral tributes, balloons, plaques, and, well, "grief kitsch," for want of a better phrase. Is this just a new trend? Or is there a harder edge to grief these days? Are people less comforted by their various religious traditions (even those that are religious), so that they are less willing to let their loved ones go? Or do they simply feel the need to invest this death with a personal meaning, since nothing anymore comes with an already-understood meaning?