Why would they ship out firearms with known issues? And why don't they inspect what they sell?
There are lots of firearms that have been made and issues discovered in SOME of them, but not all of them. The remedy is twofold. First, change the design in some way on new production guns. Second, fix the gun if a problem occurs in a particular gun. Only if it is potentially unsafe or there was a serious defect would a manufacturer be compelled to do a recall.