I wouldn’t say they’re running it into the ground. They’re in pretty solid financial footing. But they have constantly skated by on being not as bad as the competition (or lack there of). Adobe Reader stinks and the PDF format is a pig, but neither are as bad as Word. Flash largely had no competition as the other ways to put that kind of content on the web were a nightmare. Finally there’s viable competition for Flash, but PDF is still going to fly under the “not as bad as Word” banner for a long time.