I think there's a difference between grief, suffered by those close to a tragedy, and respect, paid by others as a mark of compassion over a tragedy - the searchers over this poor child, and flowers laid at the scene of a traffic accident - and finally sentimentality, where people treat a tragedy exactly like it's a cinema trip to Titanic and an opportunity to feel tearful and emote over something that doesn't cause the sort of searing, ugly pain of true loss.
The last category is not fun to witness. Ask the locals in Soham, who at one point had to contend with tour buses full of grief tourists turning up to take photos of themselves in front of the flowers. They had to be asked to stay away, as it was making a hellish situation for locals considerably worse. God knows what it was like for the Wells and Chapman families, to have to contend with that.
Locals who helped search for that little boy are paying respect, and that's very heartwarming, I think. But the woman who wrote The Lovely Bones, Alice Sebold, tells a story about visiting the town where, as a student, she'd been brutally raped by a stranger in an underpass, an event which eventually led her to write the novel. Apparently someone she met there earnestly explained that the victim had been her best friend. Alice Sebold had never seen her before in her life. And she said that was just one example of people sort of trying to co-opt the dramatic elements of what had happened to her, because variants happened all the time. And that has nothing to do with compassion.
It's weird, but a lot of people do want to sort of connect themselves to terrible events. There was a very odd bloke at my mother's religious community who always wanted to "help the bereaved" after something like Dunblane, or to "spiritually counsel" the Bulgers. He was always angling to be a prison visitor, too. I'm sorry, but that sort of behaviour is self-seeking and narcissistic in nature, and while there are lovely people who just want to convey their genuine sadness that others are suffering, it isn't wrong to question motivations, when some get some sort of vicarious emotional buzz from the very real traumas of others. That's not empathy or compassion.