This is Carmona's sixth season with 70 or more innings. Do you know how many of those seasons he's compiled an ERA+ above 85? Two of them. In 2007, Carmona had his one excellent season, with a 148 ERA+. It is also, not coincidentally, the only season in which he has struck out more than twice as many batters as he's walked. Since the start of 2008, he is 30-43, with a 5.07 ERA and a 1.32 K/BB ratio. In 2011, he has the worst WAR of any starting pitcher in the majors, only two years after having the third worst. In these three and a half years, he has a -2.1 WAR - a number that looks even worse when you consider that it was +2.0 in 2010.
Let's compare his performance, since the start of 2008, to some other more maligned pitchers:
Barry Zito gets talked about as the biggest bust of all time. Kyle Kendrick is the bane of Phillies' fans existence. Bruce Chen is on his 10th organization, didn't pitch in the majors in 2009. The only thing these three pitchers have in common is that they are all better than Fausto Carmona.
The Indians, in the midst of rebuilding, failed to trade Carmona after last season. I'm not sure whether they feared the PR hit of trading one of their veterans, or believed his good season last year was more indicative of the pitcher he actually is. Maybe they thought that he'd be able to get them more value in-season, a desperate team at the trading deadline.
Now they're stuck. They have a bad pitcher deeply ensconced in their rotation based on one excellent season, and one slightly above average one. He becomes a free agent in three months, and has been awful this year, so they're not going to get any value for him. They're unlikely to demote him to the bullpen, though they should. It's worth keeping an eye on - if the Indians end up missing the playoffs by something less than Carmona's negative WAR, it will take some of the shine of the the otherwise excellent season Manny Acta has had as Indians manager.