While you're completely entitled to your opinion, don't sit the holiday out just because it's based on a holiday in the US.

Like I said in my comment below, there's still a neat buff you can get from eating the food! And, in a way, that's getting into the spirit of things! If there's someone else at the table and they start tossing food at you, that's getting into the spirit, too! I should probably point out here that starting a food fight is NOT an actual tradition and would make your host rather PO'd-- especially if they did all/most of the cooking. lol

If you don't "get it" or understand what the holiday's about, it might be a good excuse to do a little research and learn something new! For example, there are probably plenty of people playing WoW who aren't Asian or even know what a lunar calendar is-- yet they still happily participate in WoW's Lunar Festival every January/February. I've had a lot of fun telling my guildmates about Lunar New Year when they're curious about the Earth-based version of the holiday, and sharing the stories my parents passed onto me about celebrating Lunar New Year in Hong Kong when they were kids. And, in turn, my guildmates love learning about this stuff!

All I'm really saying is, don't let a little detail get in the way of having fun or make you feel left out. There are lots of ways to get involved, even if you don't know why on Earth you're doing it. This is Azeroth! At the heart of this holiday, it's a message of coming together over a meal, sharing with one another, and celebrating... And gorging on good food :) Who doesn't like gorging on good food, right?