I'd bet most of the people saying that they don't care live outside the US or have not had to work retail.
My sister just got a non retail job for the first time and has to work Christmas Day, but having been given the choice she does not mind it seeing as her other retail job forces her to come in at 9 PM on Thanksgiving to get ready for there Midnight opening. I've worked at 5 AM the day after, been at a company that is closed & 1 year at Target were I worked for someone who didn't want to (yes all retail) and honestly did not mind any of it.
My issue with stores opening Thanksgiving day is more of an issue that were does it stop? How long before everyone's open all day or no store closes early Christmas Eve or is simply open Christmas Day? Yeah there are other places open but I would venture to say with good certainty that there are options for the employes. Where there are very few choices for retail employes when it comes to holidays, every place I've worked has even blocked out Thanksgiving-New Years for time off requests unless you get very lucky.
If you're company can run with only the people working that don't mined it, then stay open. But if you are a company that needs 50% of your staff to work for your special sales and then sends those people home halfway through the day because no one is shopping and you need to save on salary expenses then you do not need to be open that much earlier then your competitors.
Stores opening on Thanksgiving Day really need to rethink their business model, it's just sad to think that a holiday like Thanksgiving is not important anymore I mean how long before they open Christmas or stay open later Christmas eve. I'd think about the 3DS bundle at BB or Target but I WILL NEVER wait in one of those crazy ass lines. I always just wait and see what Amazon is doing anyway.