@Peedoffo I think because you are so young, and weren't around at the time, you can't really judge what happened.
A lot of the posts here are also from much younger posters and don't reflect public opinion at the time.
I am in my 60s so was very much around when it all happened.
It was only with 'hindsight' that people began to talk about the pressure C was under to find a wife. His parents were concerned about his playboy image and all the women he'd been linked with.
Of those women, many were 'unsuitable' (Catholics, divorced, not aristocrats, dodgy pasts, or they themselves didn't want to be Queen.)
The age gap is not uncommon, (I had a relationship at 21 with a man aged 35, for many years.)
The real issue was that Diana had led a very sheltered, and perhaps spoiled life. She was unwordly.
It is interesting to compare it to the late Queen, who first set eyes on Philip at 13, was engaged at 20 and married at 21. In comparison, Philip was much more experienced, had a career, had travelled , and had been in relationships.
So, from their perspective, Charles was repeating the pattern, albeit with a bigger age gap.
The world is full of mismatched couples, who married and divorced. Mumsnet is full of them! The simple facts are that C was under pressure from his parents to marry, he certainly liked D a lot, but maybe wasn't head-over-heels. Like many couples, he may have thought he'd grow to love her fully.
Arranged marriages are common in other countries and other religions. Sometimes they work, sometimes not.
She was in love, but she was immature, starry eyed at the RF, and never had a boyfriend before.
It was a bad match and I don't think you can blame anyone for it- it was a complex set of circumstances that turned out badly for them all.