Walgreens isn't responsible for providing their own police force. Sure, they put locks on the doors, but the burden of protecting businesses is on the police, which they (and we) pay for via taxes.
You could say "Oh, a business which can't defend itself against looting doesn't deserve to be in business", and maybe you end up with like 5 mega-Walmarts who can afford heavily armed guards, but this isn't actually a better society in the end than one with robust small businesses.
It's the same with cybersecurity -- you can take everyone except Google, Amazon, and Facebook off the internet, because only those three can hire top-of-the-line security professionals, but that's not actually a better internet than the one we have now.