I think people are overly sensitive about lack of mentioning of Prince Charles in Prince Harry's interview as preconditioned by the Wales' troubled marriage. No matter what Prince Charles did and didn't do, only William can understand Harry's pain here. I think people tend to put all responsibility on parents, but really a person is shaped and influenced by so much more than that. There might've been things in Harry's life that Charles understood more than William, but in this situation, only William truly understand. And I'm glad he was there for Harry.
By all the interactions we've seen between Charles, William, and Harry over the years, I think it's safe to say that Charles is supportive of his sons and vice versa. Charles did the best he could by his sons after their mother died. But he can't possibly do everything for them. Considering how Charles was raised, he's surprisingly emotionally close to his boys. Diana had an unrivaled way of connecting with people on an emotional level, and I do believe her sons get that from her more than Charles. It's not a dig at Charles. He has his strengths, but compared to his ex-wife, she was better at this than he. It's not to say he wasn't a good parent, or tried to do his best to comfort his sons, he just wasn't the right person to actively help Harry face his pains.
But back on the more important topic. Harry's struggles, and I believe that William has mentioned he was angry for a long time as well over Diana's death, will help millions of people to know that it's ok to feel pain and ask for help. That's the most important thing here. Especially considering Harry's connection to the military. There is a culture of considering certain things as weakness and not tough enough.