I don't mind places being open who have enough employees who want to work. Not everybody celebrates the same holidays, and some do but they want/need the extra pay. It crosses into "Okay, now I think it's wrong." when people are told "You're on the schedule. Be here or turn in your resignation." at an establishment that doesn't need to be open. That's not right.
At the store I worked in they started a new thing a few years before I left. They had one store open all day on Christmas, staffed entirely of volunteers. I thought that was great. They actually had more employees sign up than spots for them, so the 2nd year they opened 3 stores. Cool. The 3rd year they opened every store from something like 8am to 4pm and asked for one volunteer to cover each department (it could be anyone, as long as each area had someone) and three checkers. Hmmm. The 4th year it was decided that every store would be open, every department would have at least one regular employee on staff, and the department managers couldn't volunteer because their salary was too high and corporate didn't want to pay them for holidays. My manager confided in me that the boss told him to "strongly encourage" me to be our volunteer since my husband had to work anyway (and where, exactly would my kids be? Oh not his problem!). Yep, that's where I thought we were headed. That was the last year I worked there so who knows what they do now.
As for the customers who shop, etc. on holidays, hey I don't begrudge them going to a place that's open and staffed by people who want to be there. I did, however, resent having to be in at 5am on Thanksgiving, under threat of being written up if I didn't show, so people could yell at me because we were out of turkeys. And I'm sorry but I wanted to smack all the people who'd say "I feel so sorry for you that you have to work. It isn't right." Hello?! If nobody shopped the stores wouldn't bother opening, right? We have to be here because you choose to be here. If you want to shop, shop, but show some appreciation for the people who are at work so that you can run out for that extra tub of cool whip when the first one didn't quite last through seconds on pumpkin pie, and realize that our dinner was a "this sucks but we'll make the most of it" potluck in the break room.
Finally, take a good look at some of the stores that brag they're closed holidays "so our employees can enjoy the day with their families", but open back up at midnight for the black friday sale. What they don't advertise is that a bunch of employees have been at work since 4pm Thanksgiving day to set up those sales. They may be "closed" but they are not unstaffed!