@The OutsiderActually, I can sympathize with that, especially during summer, where they mostly demand on untrained seasonal workers who often won't show up when they're expected to because they have something 'better to do'.
So by offering discounts during their off periods often helps defer their user's frustrations and anger, by easing the strain on their own workers. That's not 'inconsistent' pricing, that addressing their users issues as best as they can during difficult periods.
But then, when I visit Wendy's, it's rarely for the lunch crowd, instead I'll pick up their burgers and then carry them home to each, or I'll stop in when they're NOT crowded (some locations aren't nearly as busy as others, so knowing which ones to visit while on the road is a sensible practice.
Summertime crowds create their own chaos, which simply calling your order in ahead of time helps to offset (though I've never tried that with Wendy's, and don't even know whether they have a 'remote order' service, having never tried it myself.
Yet living in a summer beach resort community, we're especially aware of such concerns.