I believe that this problem has been going on for a very long time and the only reason they exchange the motors is because they no the problem exists and that it is easier to deal with it on a system by system basis rather than recalling all of the systems or sending out large numbers of motors to all of the affected owners.
Yup your probably right! But, they 'are' doing the right thing, and thats important for future owners to know, even years down the road..