I think the people who go around saying Bitcoin will replace all money, that it will end wars, collapse banks and governments, etc. are slowing the adoption of Bitcoin.  When people hear this stuff they often disregard Bitcoin as anything serious and it confuses people as to what Bitcoin actually is.  The worst are the people who have some political cause, claim Bitcoin is part of that cause, and try to imply that anyone who uses Bitcoin agrees with them and supports their cause.