Hmmm, lumping Harry together with Andrew is a bit of a giveaway isn't it.
I mean it's obvious to avoid potential monarchs who would end the monarchy. While there're likely plenty of people who don't want Megan Markle as queen because she's "Black", I think there're a lot more people who have looked at the last few years' Harry and Megan circus and thought that even for the British monarchy it was undignified (likely because they have forgotten Ferguson).
This suggestion is clearly to get rid of the most public embarrassing people in the high end of the succession.
