If Adverbs are considered bad writing, why are they found in published work?

Ever since I read about the "No adverb rule" I began watching for them. They're on every page of the last three best selling YA novels I've read. I'm looking at "City of Bones" right now and I can count 8 adverbs on a single page. Some in description, some in Dialogue tags. The rest of the pages are littered with them as well. So I don't understand why this rule seems to be so strict... when all of these so called "bad writers" are simply ignoring the rule and laughing their way to the bank. Maybe I don't understand the "No adverb rule". Can someone please explain? If it's so bad then why is it in best selling published work?