WHY THE BAD REP? Spinach leaves are bitter. And some consider it way too slimy once cooked.
THE FIX Counter the bitterness in a salad with something crunchy, like croutons, slivered almonds, even a few bits of turkey bacon. Also, almonds, chunks of minced garlic, or something acidic (like vinegar) can help to keep cooked leaves from feeling slimy.