If there is a deficiency in the fork (bending above the disc brake mount), I suspect it is a design flaw rather than defective manufacture or lack of QC.

For example, I (and others) have wondered if Surly took the std LHT fork and simply added a disc mount + housing guide + deleted canti bosses, or did they select a thicker-walled tubing for the fork legs to withstand the increased bending force from a disc brake. The outer fork leg diameter on LHT and DT forks appears nearly identical based on my measurements. My DT fork diameter is larger only for the bottom 3cm where the leg is brazed to the dropout. I don't know if all LHT forks are this same diameter now, since they were redesigned when the DT model appeared in 2012. The new LHT fork has different dropouts, and fork crown with 5mm bosses for rack fitting.

Salsa recalled a front rack last year - when I first saw it I thought it was way too light to hold up under load. I bet the next few generations of Salsa racks and forks will be beefier after the QPB accountants have determined the total recall costs.