"Darwinian mechanisms are useful for explaining antibiotic resistance but not the origin of the immune system. They are OK for changing the dimensions of finch beaks but not for constructing beaks. They have some value in elucidating industrial melanism but not for engineering structural colour in moth wings." -- David Tyler
This is what might be considered the "common sense" view. A lot people with no axe to grind instinctively question the creative powers of the darwinian adaptive "mechanism".