The Queen is conflict avoidant, it was always Philip that played the boogeyman, it is understandable, she was born in a environment where no one opposed her, Philip had to learn that there are people who will "disobey" and twist the rules for selfish reasons.
Life gave the Queen lessons, and she was able to see things, but understanding the origin of the problem, or the consequences would be hard. She is one of the most documented people on the planet, and from this one thing can be established as a fact, it is hard to understand the outside world when the only interaction with it are controlled by others or lead by one's position, in her case being Queen.
The above doesn't make her incompetent, but it certainly enabled her mindset," if we wait long enough it will go away. "
The problem is that news travels instantly, and at her age there will be to many "yes men" around.
Charles is incapable of making decisions, is easily cornered and now will be frightened of pressure against him or Camilla.
For someone as smart as him, reading the room never got further than Markles level.
Leting the Harkles back in, either after public pressure, media pressure or Harkle blackmail will come back to bite them.
The aftermath of divorce from Diana, after paying a hefty sum, after her staying at Kensington, after ofering her the treatment of the mother of a future king, didn't stop Diana from fantasising about being a American star, rolling on yachts of arms dealers, meddling in politics, overshadowing Royal events, no it got worse.
And Harry wants revenge, it was clear directly after George was born, it got worse with the other two.
news.sky.com
Not forgetting that 
