I don't think that would reflect badly on them. You're right that Harry's and Meghan's behavior has been comparable, so if it were just about that, they should be equally annoyed with both. But it isn't just about that. Harry is their close relative whom they've always loved, and with whom they've had a lifetime of good memories and experiences that help to balance out the bad. Meghan is someone they've known for just a few years, only really spent time with for a year or so, and it sounds like most of that time wasn't a good experience for anyone involved. Of course they're going to be more forgiving of Harry than of Meghan, because he's their child/grandchild/sibling and Meghan is just the person he married. I think that's pretty normal.