The possibility of ribavirin resistance when used without interferon could be a factor. There's also a moral hazard issue to the FDA approving a combo that works in half the patients and GILD profiting twice upon retreatment. There's no competition in these genotypes.
GILD–I'm not even sure the 7% difference doesn't show stst-sig non inferiority to SOC.
The inferiority of the all-oral arm to the old SoC was non-statsig, according to yesterday's CC. Still, I agree with oc631 that Sofosbuvir + ribavirin for 12w doesn't cut it in genotype-3.