Because I was never ga-ga about Diana. I'm not saying I hated her, only that I didn't engage in the excessive worship of her that other people had. She was this woman famous for marrying a crown prince. Big woo.
Also, not long after the extravaganza wedding of Charles and Diana, I dated one of the youngest sons of a Middle Eastern royal family, and learned how life wasn't all decadent pleasure for them. Maybe now things are different, but, back then, they didn't have many choices, about anything. Their lives aren't theirs. They belong to tradition and obligations and can only do what will not bring shame to the crown or to the country.
They can't decide what to do with their lives, from the schools they attend to the friends they're allowed to have to what qualifies as their royal duties (observe how royals don't become doctors and engineers, even if it's what they'd wanted), and even who to marry--and why.
Sometimes a royal gets lucky, and falls in love with someone who ticks all the boxes for the kind of spouse considered suitable for an heir to the throne. That was the case with QEII. Her son wasn't lucky that way. He met and apparently did the nasty with Camilla without the blessing of the marriage sacrament--horror of horrors! That made his family so opposed to her that they arranged for Charles to go on an overseas tour with the military. But wait--that's not all! They also pressured Camilla and Andrew Parker Bowles to marry, by getting their parents to post an announcement of their engagement--even though Parker Bowles hadn't proposed at all. He got the hint and proposed, and she got the hint and accepted.
And then Charles married Diana, the one who ticked the boxes--virgin, no scandals in past, CofE, from a respectable and well-to-do family (rumours have persisted for decades now that QEII was adamant that Charles marry a Spencer), white European, and oh--yeah--a virgin. Whether or not he liked the woman was near the bottom of the list. And they made each other miserable.
And then people are surprised when it all went bung?
I don't take sides in this at all. I pity all three of them for their needless suffering. All that sturm und drang and for what? To appease malignant, patriarchal notions about who a crown prince could marry. It boggles the mind that people could still think those idiotic Medieval standards mattered in the latter half of the 20th century.