I know several people like this and it drives me bonkers. They are so hard to cook for. It makes my mind boggle. I hear people moaning about what to cook, you suggest something and then you get 'oh I don't like veg' Dig a little and you usually get a list of exceptions such as tomato pasta sauce, or they might eat carrots.
I just flat out do not understand how it is possible to not like every single vegetable on the planet cooked in every single way you can think of? Because that's pretty much an infinite number of tastes. I'm probably being unreasonable with the sneaky thoughts I have about the 'veg' that must have been served up in their house when they were kids to make them feel this way. I'm probably not being unreasonable to worry a little about their health.
But AIBU to want to strap everyone who claims this down and forcefeed them a hundred varieties of scrummy vegetables cooked in a myriad of delicious ways?