The original plan was for the r179's to replace the r32's. If the C wasn't originally getting r179's, then the C would have kept the r160's that it had. A lot of C train riders demanded NTTs on the C. There are even newspapers articles in the past that even talk about the C always getting the oldest equipment (r10's, r30's, r32's, etc).
And yet there are haters (mostly E, F and N train riders) that are criticizing and complaining about the A and C trains getting the r179's and r211's.