u003cbr/u003eBecause it's been overcooked. Seriously that's the only reason why. When cooked properly there should be no lingering cabbage smell in your house. The strong smell many people associate with cabbage is due to hydrogen sulfide. But the good news is that you can only smell that rotten eggs like smell if the cabbage has been overcooked, or allowed to braise for too long. If you want to braise cabbage, I suggest you try an Instant Pot Cabbage recipe instead, to contain the odors in a closed environment.