It goes something like this, bike company marketing man sits in an office thinking of ways to push new product because sales have dropped due to bikes not really changing much over the last half a decade or so.
decides to lob some flatbars on a cyclocross bike and the yank fireroad warriors go mad for them.
finance department notices they are selling well so decides to slap the same big wheels on anything they can get them to fit into accompanied buy a few million pounds worth of advertising budget – yanks go even more mad for them. unfortunately there is a point in suspension travel and bike type where they stop working so 650b is adopted – not really big enough change to make any real difference to handling but big enough not to fit into current frames and forks properly the perfect product to sell some more snake oil to the people that must have the latest bit of kit that bike gaydar is advertising.