It spent too much on solutions that were ineffective. Moving to police that can make arrests, as the article says they're doing, should be more effective, assuming that the authorities will hold the arrested crims.
Also something not mentioned is that these security measures are also hostile to customers. No one wants to feel like they’re shopping in a prison.
And at these locations where they install the cases, you have to wait for a person to come over and unlock it, except they also didn’t increase staffing to deal with all of these case opening requests.