A lot of smart people are worried about Bitcoin's increasing importance and value.  They worry that all bitcoin is doing is simply taking money from elsewhere in a speculative frenzy, chasing what is an irrational bubble.

In particular they use the classic zero-sum argument that says that for whoever makes $1 from bitcoin, someone else has lost $1.

Well, in pure accounting terms this is true.  But if Bitcoin represents a beneficial new paradigm in global finance ( and the world certainly needs one!) , then Bitcoin can be adding economic value to the world. 

How does this work ?  Just like any company that builds a better mouse-trap.  People rush to use the new product as it uses less resources than before.  The surplus economic resources represent true global profit.