Expanding one's market and potential audience is always a good thing (whether the specific plan or product works to do that is the question), so DC being able to sell comics in another store beyond the usual suspects isn't a bad idea in and of itself. If "hardcore" comic readers are going to be ticked that people can buy Batman issues outside of the comic book store (which is already an established thing), they need to get over themselves.
Seeing as we all come to the hobby through different paths, I'm not sure we can generalize this kind of thing. Besides, at the end of the day, if DC's makes back their investment in the deal, it's already proven to have been worth their time and a good business decision.