That and not keeping up with changing food expectations of a lot of consumers. Around here, Chipolte's, Panera, DiBella's Subs(a smaller chain) and even Arby's among others are offering some healthy bread options, fresh vegetables, preparing their own foods on site. They're being rewarded with long lines at meal times.
How to explain Subway? Gross meat sitting in some liquid concoction that tastes like soylent green. The smell of the place makes me gag. My some worked there and he reeked of that “smell”. What’s the attraction?