If I'm not wrong OP should change the way he introduce bitcoin to new people. Atleast prior to introduction we should understand what kind of people we're talking with. Not everyone have the mind to accept it, when they've got good sum of fiat. Maybe thats the reason why uncle keeps saying something against bitcoin. It is always necessary to make some connect with the public regarding bitcoin. One should not expose that he's bitcoiner. We should simply introduce about the existence or while discussion happens relative to technology.
You make a valid point that we should think carefully about to whom we introduce bitcoin because many people don't care much about making money and believe that everything is ponzi scheme. I have seen situations where people start blaming the people who introduced them because bitcoin hasn't yet lived up to their expectations. Despite how interesting it is to invest in bitcoin it also has its own risk. And the majority of wealthy people don't think investing in bitcoin is important. In my opinion, investment in bitcoin should be based on what everyone understands and should be a personal choice.