This is an exaggeration of what (I think) happens: all of their current customers only ever drive there and park in front of their shop. They say oh with no parking I won't come any more. Then they stop coming. They lost all their customers! Everyone who can now safely walk to the shop (who couldn't / wouldn't before for multiple reasons) starts walking there. There are a lot more people who can now safely walk to and patronize the shop, and they do. The shops foot traffic went up by 10x. They still lost all their customers.
I think it's probably good that it's easy for people to walk / bike / bus to this shop, and the shop owner probably does to, but they still may have lost a lot of old customers.