I don’t like the term. Diana was a symptom, not a cause. She reflected Britain in the 1990s. Perhaps a better word would be infantilization. As Cicero said, to know nothing of what went before is to remain forever a child, and Shirley Williams’ destruction of the time-proven British education system ensured that would happen to every child born after around 1965 who was not lucky enough to escape her monstrous replacement. British adults behave like mawkish, self-centred schoolchildren everywhere. There used to be some institutions that knocked the childishness out of them, like the Navy, but it appears even those are falling.
Chris Dillow has some other interesting observations, although I think he confuses laudable individualism, a British virtue, with the vice of self-centred idiocy, which is evident in the highest reaches of government these days.