I've worked in hospitality for over 5 years, and I can confidently say vegans are my least favourite group to serve

No other diet had people showing up with a booking that didn't mention the diet. No other diet has people ask for a custom-made dish on days where the chef is already running around stressed out of their mind. It's just vegans

It comes across as entitled. So you're right. In my line of (past) work, vegans won't tell you they're a vegans until it's too late

To be clear, this was on a set menu we could do a vegan version of, but only if we were given at least a days notice beforehand. And we never were