When you work on thin margins a lot of things can convince a store to move to greener pastures. Declining sales, higher overhead, saturation of slip and fall claims, it doesn't take a lot of these to make a store lose money steadily.
Read that they are closing 68 stores nationwide. If you recently purchased a membership, you can get a refund. Going to concentrate on stores that are actually profitable, and claim they will turn some old stores into distribution centers for their online business.
We've thought the quality of products and personnel has been declining for a while. Some of our business has certainly been going to competitors (CostCo) and online (Amazon).