This article confused the hell out of me. Since I don't eat apples but my kids love them, I have purposely tried all the kinds of apples at the store. And time and time again my kids prefer Red Delicious.
Might be related to the childhood preference for sweet foods - apparently Red Delicious has high amounts of sugar, relative to other apple varieties. For example, 14.8% sugar for "Early Red" variety[1], vs 10.4% average over all kinds[2]. Maybe this is enough to explain it?
This is maybe not inconsistent. Kids like Kraft macaroni and cheese and Hotdogs covered in ketchup. We shouldn't expect kids to like "better" foods if they haven't developed a palette yet.
My kids nag me to buy "cheese product" which is like cheese but 10x the price (OK I'm exaggerating, it's 5x - cheese is already the most expensive single item of food we buy), tastes like plastic and is marketed in a kid-friendly way.