The Royal Family do not want or accept stories of "rags to riches." While they may respect a person with a heroic story, or they may find such a person useful to them - such a person is still low-born, generally suspect and not suitable for their family.
This kind of Haratio Alger story is purely an American notion.
Having said that - they would have respected Meghan if she "knew her place" as the brassy American actress wife of the 5th in-line to the throne, kept quiet, didn't talk about them publicly, if she didn't embarrass and humiliate them, wasn't a gold-digger and Harry wasn't an utter fool.
If Harry wasnt an utter fool, he wouldn’t have looked twice at MeAgain...
Tom or Dick would have been the utter fool...