The brukiew, often the only solid ingredient in a big pot of water cooked into a thin swill, was a concenetration-camp standby
I'd heard of the bad WWIII poverty conotations but not the concentration camp ones. To further banish the vegetable they created a myth that it's hard to digest (this, from people who combine vodka and boiled potatoes).
The mother of a very good friend won't eat rabbit for the same reason, it reminds her too much of WWII or post WWII poverty when it was almost the only meat available....