Update - since I keep having to repeat myself I would like to clarify that this is a general thing during the holidays, not just AFTER Hanukkah and it's not just strangers, but people I know as well. This means when people talk to me about the holidays and ask me, I explain that I'm Jewish so I don't have Christmas plans, they go silent and uncomfortable like it's a bad thing.
One more thing, I do say happy Hanukkah in return and I still get a dirty look. The entire point of my post is to find out why people don't like it when people are Jewish or simply don't celebrate Christmas. Since when is this so important?