The statement is in reference to the fact that most people coming out of General Surgery residencies do further fellowship training and that general surgery is no longer as "general" or broad based as it once was (ie, with surgeons doing ortho, gyn procedures, etc.).
There will always be a need for good general surgeons but they don't cover the broad spectrum of cases like they once did, except perhaps in more rural areas. Vascular cases are now generally done by Vascular fellowship trained surgeons, Colorectal cases by colorectal surgeons, etc.