Interesting - but extremely biased towards a vegetarian's outlook. I agree on some levels and think useful things can be taken from your comments, there is absolutely a problem to be solved here, but I feel very excluded by the stance you take. Perhaps between us we can make something truly inclusive?
I am an enthusiastic, but reasonably fussy and (I try to be) ethical meat-eater. I am married to a vegetarian, which has fundamentally put me in the camp of those picking through menus, arguing with French restaurants about the clear traces of removed bacon, etc. I get it, and I find it unacceptable that in 2017 people pay so little care to the basics of providing inclusive food for any size of event.
Being born at the end of the 70's, my childhood diet in the 80's was nothing like the middle-class foodie nirvana my daughter enjoys. My dad being highly averse to onion, garlic, pepper, just about anything that gives veggie food colour and interest, dampened any creativity around vegetable preparation in my home. Meals were often meat, carbs, 2 veg (boiled to death). Not saying my mum didn't turn out nice balanced meals too, but frequently I had a plate which contrasted meat and carbs that lit up my taste buds, and veg I had to endure past gag reflex, it was so bad. Salads were not actually as bad, but devoid of dressings etc, bitter watery tastes of iceberg lettuce and celery dominated. I am chemically programmed to react with violent distaste towards foods which remind me of this. I eat a lot of vegetables now, but there are still a few I cannot stand.
That's not an unusual story, I'm hardly a victim of abuse. Ask around, it's what a lot of people experienced who grew up at that time. Echoes of post war rationing etc.
These days, at home we eat a largely Mediterranean diet. I cook a mean aubergine lasagne, prepare salads the way my French friends taught me, and actually enjoy many vegetables, prepared right.
But buffet sandwich stations are still a minefield for me - plates of BLT with wilted iceberg and barely orange tomato, dampening the bread with bitter watery juices. I'll pass. I am not suffering castration anxiety, and find that wilfully sexist. Plenty of women feel the same way. It's puking-in-front-of-peers anxiety, I'm not concerned about my bits at all! I'm mostly over it, but there will always be a little background anxiety that I'll be able to pick up a sandwich and, perhaps while talking with someone important or interesting, eat the sandwich in a decorous manner without noticeably gagging or having to conspicuously leave bits behind.
So I fall into your category of silly, it appears. But there's not a lot more I can do about that - marketing has nothing to do with it, and literally bitter childhood experience has everything. In all my empowered food choices (not including the 23:30 back from Paddington...) I try to pick out nice veg, and meat in moderation.
At the buffet sandwich station, my saviours are the prawn mayo and salmon (ideal, if you ignore Monty Python), the egg & bacon (great but not healthy every day and can have eventual consequences at an all day event) and the cheese sandwich, which I share the Venn diagram overlap with the veggies but not the vegans, who are usually screwed.
How to fix the problem?
Cater for all, make people DIY a bit, and give them better tools and layout.
Make-your-own-salads! With decent fresh ingredients. It's truly not that hard to do even at a big event. A few meaty bits like bacon can be supplied. BUT... keep the quantities put out at a time low, or some people will trough it! And placement is crucial - vegan stuff first, and meats go at the end of the line! Then, the meaty fingers can't mess with the veggie purity. Dressings! Colours! Encourage those default carnivores to try the pretty, obviously healthy options. No nuts in anything - guarantee it. Demand your supplier guarantees it.
Pizza! Base + tomato only ideally for vegans. Supply the cheese, and toppings separately. A fondue keeps cheese warm, and the resulting pizza will be much nicer.
Sandwiches! Plain halved rolls/baguettes, choice of butter/oil/spread. It's possible to combine the stations so the salad ingredients/toppings etc.
All of this demands far more time in the queue though than picking up the marked brown bag. But it's really, really good quality time. It can displace advance preparation time if planned right, prevent waste and if more venues and events did it, help our health.
My poor background food programming is badly triggered by catered events. That bacon sandwich lights up my primitive brain and amplifies its demands next time I'm shopping, sometimes enough to break a run of healthy eating. Whereas I can enthusiastically fill my plate with cous-cous, fresh tomato (still OK vegans), egg (still OK veggies) and only sprinkle a reasonable few bits of bacon at the end, which I could also happily do without these days, but others may really find to be the thing that gets them choosing the salad line.
I think event catering occupies a pivotal place in forming our eating habits. It is mostly a force for bad now, but could be an inclusive force for good. Let's not use it to force our points of view, but offer genuine, healthy choice!