@Mountain Cat - it was all so petty - everything from what day we were having it to how we did the sign-up sheets to cleaning up. No matter how we adjusted things to accommodate one set of complainers, just like whack-a-mole, a new set of complainers would pop up next time.
The largest complaint, by far though, was the food. We had a lot of Indians in the office, and most of them were vegetarian, and if it looked like there were more vegetarian dishes than meat dishes (especially vegetarian main dishes), then look out, the complaints came fast and furious: "Why are we catering to
them? They're in our country, they should be eating what
we eat!"
That, and some of the Indian workers were temp, there for 10 days or so, living out of a hotel, and so we didn't expect them to cook anything and of course they were invited, and that wasn't well-received: "I checked the sign-up sheet, and I don't think that guy brought anything, but he's eating! Do something, TastyReuben!"
Even the meat dishes, unless they were good ol' Midwest-friendly things, didn't escape scrutiny. Anything "foreign" largely was left untouched by some of the locals, and they also complained about that.
Barely-disguised prejudice, AFAIC, so we stopped doing them altogether.