The point is not what stores that gets looted. It's that stores are being looted at all. This only happens when people feel they are not being heard and when there is no other action than rioting and creating chaos. Looting happens because of the "protection" of the chaos, but you have to look further than just seeing people stealing stuff from stores.
The issue is so much larger and the system is actively forcing the people to create chaos, because there are no other way to get the leaders to listen to them.
People have been trying to fix this problem for decades now. Still the police is murdering US citizens. Of course people are gonna get mad as hell when that still happens.
Don't be naïve.
(Which is orthogonal to the legitimacy of the protest itself).