There is a genetic reason some kids are “picky” about eating vegetables, or at least some vegetables. And we all know we should consume more veggies than we do. It seems the sensitivity to “bitter” tasting is genetic, with some individuals more sensitive than others. Kids who are more sensitive tend to be more likely to eat sweeter veggies (e.g. carrots and bell peppers) than bitter ones (e.g. broccoli and cucumbers).
Realize there is some “use” to this sensitivity evolutionarily. Most naturally occurring “poisons” are bitter tasting, so someone highly sensitive to “bitter” is more likely to survive (and would be good at the job of royal food taster).
There is hope of expanding food options/choices, nonetheless. As one of the study authors pointed out, food preferences often change as we get older. This has been borne out repeatedly as my kids have aged and matured, although I’m not sure when I will be able to get them to eat a turnip or certain meats that look like the organ they came from.