I'd actually empathize better if that had been the argument - I'm not even strictly vegetarian but it's not unusual for work-related social functions to operate on the assumption "everyone eats meat" (with maybe an occasional exception). The last such event I went to I didn't drink (not a major issue, I was fine with sparkling water), but nor did I wish to eat meat (which I do maybe once a week at dinner - this was a lunch). That proved basically impossible as it was share plates and all but one (which I insisted on, despite objections) had meat.