If you’re not into them, then don’t partake.
I never B”N eat at kiddushes. I make sure to have some coffee in the morning. That way, if my family or guests come really late from such a kiddush and we start after chatzot, then I will not have fasted on Shabbat. In fact that’s what happened this past Shabbat.
As far as what people do, I’m not to judge negatively. People want to include others in their simcha, which is a nice thing. I still try to thank the host, even though I don’t eat. They still put out food for me and included me in their simcha.