Mmm... No, not really. Now Columbus Day, that's a day of mourning. But Thanksgiving was simply a day to celebrate a good harvest, same as the Spring Festival in China, or many others in tons of other cultures. It really had little to nothing to do with the Native Americans, excepting the fact that the Native Americans helped them make the harvest possible. Even if they hadn't, the Europeans would've figure it out on their own and gone around killing people eventually. As it was, it probably helped maintain the peace a little bit longer.