Because the European safety regulations require the additional securing points for saw blades, our saws have this feature and our German made Leitz Destroyer blades have the holes for this reason. 

Harvey table saws and blades come with that design, due to the safety advantages they bring when the blade is spinning, but if you wish to remove the two additional screws to be able to use non-European saw blades that do not have the holes cut out, this is also considered acceptable by USA safety regulations and standards.