Profit, pure and simple. If people are willing to spend money on the convenience of a digital copy then publishers are going to charge full price. They get more per unit sale as there are no retailer, packaging and manufacturing costs plus it can't be re-sold, so they're incredibly happy charging full price. We get screwed but they get cash. Plus it keeps the retailers happy as they don't have to compete with low digital prices.
Of course the other side of it is the PC side, with Steam/Green Man Gaming sales where they sell an older game for a ridiculously cheap price in the hope you'll become a fan and purchase the next iteration of a franchise for full price (and more profit for that digital sale). Much more consumer friendly. Plus retailers don't care because they pushed consumers to digital by not stocking PC games anyway.








