My question is this...
His logic is that he deserves security because he is the child of the Monarch.
Anne, Edward and Andrew were all children of a monarch and didn't have these security functions.
It's not that long until George and CHarlotte start taking over duties (when you think H has been arguing this for five years, that time will pass quickly). In which case, Harry's relevance in the royal family becomes even lower - add in that he will go lower down the line of succession in coming years, I don't think this could ever be a win for him.