I actually agree with the author.
They don’t replace mashed potatoes. They are a great complement. Always serve both on Thanksgiving. If anyone is ever on the North Fork of Long Island from April to Dec the Modern Snack Bar makes great mashed turnips and sells them frozen.
Turnips can be subbed for potatoes in soups and stews, but so can radishes.
Radishes can also be used to make a really good faux-tato salad. Boiled, chopped eggs, pickle relish, minced onion, mayo and a bit of mustard added to steamed or braised radishes (well drained and patted dry), dash of cayenne, salt and pepper.
Peach
I seldom eat potatoes because of the carb count. I've used turnips as a potato substitute in soups and stews; don't think I've tried them mashed. I do prefer mashed cauliflower to mashed potatoes. To me mashing is the least flavorful thing one can do to a potato.
Except turnips are very high in OXALATES, which is a natural plant poison that can ruin your kidney by creating kidney stones while the stones can result in breast cancer, kidney disease, heart attack, etc.
TURNIP GRATIN is also really good!!!!