If there were items on the menu I'd be happy to eat, no problem atall.
I'm a meat eater, but so do sometimes choose the vegetarian option, prefer vegetables on pizza, so I'm not overly fussed about meat having to be a part of a meal.
What I can't stand is fake cheese, fake meat, tofu...
So if I could eat something that was entirely potatoes, veg, salad, I'd be fine with that. But I can't stomach the fake stuff.
Whenever my group of friends go out we share ideas for restaurants and always ask our vegan friend to look at the options and check she is ok with them. If they are shit, or just a token offering that she doesn't like, we don't go. We always manage to find somewhere that suits us all, or revisit somewhere that's been good in the past.
Being vegan is very restrictive and I wouldn't expect a whole group to pay for a meal they're not happy with for one persons choices. In the same way I wouldn't expect someone to go for an Indian, Chinese, Italian, if they didn't like that cuisine.