Hilary Mantel had a good essay in last weekend's Guardian on it -- she argues that the Diana being mourned was a sort of public myth that had little to do with any actual person, that she was in a sense a collective invention:
www.theguardian.com/books/2017/aug/26/the-princess-myth-hilary-mantel-on-diana
A deathbed, once, was a location dense with meaning, a room packed with the invisible presences of angels, devils, ancestors. But now, as many of us don’t believe in an afterlife, we envisage no final justice, no ultimate meaning, and have no support for our sense of loss when “positivity” falters. Perhaps we are baffled by the process of extinction. In recent years, death narratives have attained a popularity they have not held for centuries. Those with a terminal illness scope it out in blogs. This summer the last days of baby Charlie Gard riveted worldwide attention. But what is the point of all this introspection? Even before the funeral, survivors are supposed to flip back to normal. “Keeping busy” is the secret, Prince William has advised.
Grief is exhausting, as we all know. The bereaved are muddled and tense, they need allowances made. But who knows you are mourning, if there is nothing but a long face to set you apart? No one wants to go back to the elaborate conventions of the Victorians, but they had the merit of tagging the bereaved, marking them out for tenderness. And if your secret was that you felt no sorrow, your clothes did the right thing on your behalf. Now funeral notices specify “colourful clothing”. The grief-stricken are described as “depressed”, as if sorrow were a pathology. We pour every effort into cheering ourselves up and releasing balloons. When someone dies, “he wouldn’t have wanted to see long faces”, we assure ourselves – but we cross our fingers as we say it. What if he did? What if the dead person hoped for us to rend our garments and wail?
When Diana died, a crack appeared in a vial of grief, and released a salt ocean. A nation took to the boats. Vast crowds gathered to pool their dismay and sense of shock. As Diana was a collective creation, she was also a collective possession. The mass-mourning offended the taste police. It was gaudy, it was kitsch – the rotting flowers in their shrouds, the padded hearts of crimson plastic, the teddy bears and dolls and broken-backed verses. But all these testified to the struggle for self-expression of individuals who were spiritually and imaginatively deprived, who released their own suppressed sorrow in grieving for a woman they did not know. The term “mass hysteria” was a facile denigration of a phenomenon that eluded the commentators and their framework of analysis.