I've seen that more independent scenario play out as I have the ungrateful kids who had a lot of help from their parents to the point of enabling. After certain point all the adults in the room shouldn't be relying on or rationalizing their upbringing or what others had or they didn't. As adults it should be a clean slate and it's those adults that decide what to write on it. If they want to write "I don't care", 'My way or the highway" or "Screw you" so be it.Considering what they have to deal with many do ok.
Believe or not most people can chose what karma train they'll catch a ride on. Problem is most stick with the decisions they made decades ago.