There is something behind the 'humanizing' that Harry does, of his grandmother, father, brother. These are his immediate family members, and it's quite apparent that to him he sees their relationship to him as the single most important fact about them. Not their 'jobs' or roles, but their existence as his grandmother/ father/ brother. Every child needs strong connections with parents and ideally siblings/grandparents to grow up mentally healthy and strong. I can't imagine that being brought up the second son/younger brother of a future king is easy in this respect, and perhaps what Harry is seeking to do by humanizing these three people is strip them of the hoopla and fluff and expose them as people, the people he had to grow up with and at whose feet he clearly lays the blame for his discontent.
However, he doesn't seem to realize or understand or accept or want to buy into the fact that to the hand that feeds them and him (ie the public - not going into the civil list question, they are immorally rich only on our sufferance and they know it), MORE than mere people, these three individuals are monarchs or monarchs-in-waiting. They're not meant to be dehumanized as far as the public is concerned. Their purpose in life, as far as the public goes, is first and foremost to be figureheads. We are meant to suspend our disbelief, deposit our faith and loyalty and trust in them, use them as unifiers in a divided nation to keep the nation's values and moral stable and on track. They're only allowed to be human people in their private lives (which is why tabloids love dishing the dirt on their private lives, because it's what we're not meant to see).
Harry is doing the tabloids' job for them. He's bringing the monarch and monarchs-in-waiting down to regular people who have weaknesses and failures and really just people who aren't all that. I mean, we all KNOW this already, but here in the UK we love to willingly suspend that disbelief. That's why Kate has been so successful: she doesn't SAY anything or DO anything substantial, she looks inoffensive at all times, there's just nothing there. She's the perfect repository for the public's aspirations and high standards of woman-hood and motherhood and family and virtue.
I think this also explains some of the myopia around Andrew. Everyone knows he's disgusting. Everyone knows he's a disgrace. But nobody is braying for blood because, as long as he goes away and keeps his mouth shut, we can forget about him and continue to believe the fiction of the monarchy.
Of course, the republicans amongst us, anyone with an iota of intellectual honesty and moral probity sees through this and is a million steps ahead of everyone else. Harry is doing republicans a huge favor, digging the monarchy's grave for them.