I think that stores should be closed on Thanksgiving. Employees should be allowed to spend the day with their family. I think considering how early the stores open on Black Friday they should be able to give them Thanksgiving off at least. Thanksgiving is supposed to be about family not shopping.
As someone who's worked holidays in retail, it can be a stressful, depressing situation to have to go in and work a ten hour shift instead of spending time with family one might be able to see once a year. Holidays, especially Thanksgiving, are a time for employees to unwind, visit with people they haven't seen in a while, and enjoy their families for at least a day. Some employees don't even have an option to ask off for Thanksgiving and are forced to miss out on food, yearly traditions, and important time with their significant other, children, parents, and extended family. If more stores simply closed for one day, employee morale would rise and holiday turnover wouldn't be as high.
In my personal opinion I believe more stores should close of Thanksgiving Day to give more people the opportunity to celebrate this occasion. This day is important for people in the United States and Canada as a day of giving thanks of the harvest and giving blessing for the following year.
There is just no reason for a store to close on Thanksgiving. Stores can make money on the holiday by catering to people who want to shop. Many people who are celebrating Thanksgiving appreciate that they can go to the store to buy anything they need on that day. There are also people who do not celebrate Thanksgiving, and don't want to be affected by it.