There's a lot on this thread about MM's family. Harry and William's isn't that squeaky clean.
The difference is that the Royal family don't disown their relatives, as Meghan Markle has tried to do. And considering she and her husband have spent recent holidays in Nice, Venice (with the Clooneys) and Ibiza, they could have spared a few days with the rest of the family in Scotland, instead of snubbing the Queen for the second year running. It is not as though they are working, although apparently both 'have an extremely busy schedule'.
This trip to America, for a tennis match strikes me as a an attempt to show 'I am an independent woman'; instead she appears a very rude one.