sounds like yours is not the norm.. I have had 2 sets 1 for 5 years with 40k on it still looks new only slight surface rust around welds for the hangers
the other has been on a beater monte carlo that has seen every snow we had (love donuts in the snow) never washed it off ever car is a total rust bucket exhaust still looks great and does not leak.
No I do not work for hooker.
I have seen some flowstopper cat backs rust apart, Nothing is ever going to outlast SS as long as its welded with ss rod.