It's very possible that JCP want to have their stores Internet enabled for other reasons, and thus the ability to offer Internet to customers is just a side benefit of that at (possibly) no additional cost.
> If I'm in the store, how about making my experience shopping at the store as good as possible and not tell me to pull out my phone to make it work?
Not everyone in the store is there to shop. It could be a competitive advantage to have these non-shoppers urge the shoppers they go with to go to JCP instead of some other place.
Also, it is possible that giving Internet access to shoppers is easier/cheaper than making the experience in the stores as good as possible. If I want to comparison shop, for example, I wouldn't trust information given to me by the store I'm in, I would pull out my phone.