The royals have always been ridiculed. The children as the figureheads adds to the derision, it's mere satire and it's been done before.
They raise their children in the limelight, unfortunately it comes with the territory. Harry and William experienced similar as children, do we not remember their faces plastered across the tabloid, was that not the 80's equivalent?
The time Diana furiously dragged Harry away from a car window for sticking his tongue out at one of the paparazzi who did it first because the headline would be about how naughty he was?
For as long as the royals stay in power they will face ridicule. Harry has little influence over that, I would say the Crown adds more to that than he does. There was a spoof of the royal family a few years ago that featured William, Kate and Harry and I'm sure George was given a few gags. They are consistently derided as stupid and money hungry, that was a stereotype there long before Harry.
There is a huge hypocrisy around mental health in the media, one moment it's 'be kind' and the next it's 'nobody is above critique' - this is a perfect example.
They will argue this clearly isn't about the children and I imagine that media laws are in favour of the tv producers. The creators will have had to receive permission for this to go ahead to avoid lawsuits and the like, therefore by Harry speaking out he would just add further fuel to the fire.
If you don't like it sign one of the petitions going round but further perpetuating 'Harry did this, Harry did that' is simply drawing the royals, and by extension, the children into the spotlight. Similarly to the way speculation about Diana in 'she did this, she slept with him' she gave an interview to absolve the speculations and it only made it worse. Sometimes silence is the best course of action.
They feature the kids simply because it sells, if you don't like it, don't talk about it and don't watch it and hopefully others will do the same and the ratings will plummet enough to be cancelled. The constant blame game is pointless and last week's news.