As I imagine it, there were exactly two people on this earth who welcomed the tragic death of Matthew Crawley at the end of Downton Abbey's third season. The first, obviously, was Julian Fellowes, who seems to take great pleasure in killing off the characters of anyone who dares to dream bigger than Downton. (Though maybe Dan Stevens could have been a little more grateful.) The other celebrator — in my head, I repeat — must have been Hugh Bonneville, who could finally say, with something approaching conviction, "This wasn't Lord Grantham's fault!" I realize as I type that I actually do not know this for sure; season four may well reveal that Lord Grantham had become interested in car mechanics and had been tinkering with the roadster just before Matthew drove off to meet his first-born child. But otherwise, Lord Grantham is in the clear, which is a new and strange situation for him. He is usually to blame for most everything that goes wrong at Downton Abbey.
Let us start at the beginning, with his more obvious screw-ups: He is mismanaging the estate; he loses all his wife's money in a stupid Canadian rail investment; he ruins Bates's murder trial and gets him thrown in jail for the better part of the third season (and oh how boring that part of the season was); he kisses a maid; he allows a fake-amnesiac burn victim into his home; he is always yelling at the women of the house for having an interest in politics or wanting to help the disadvantaged or doing anything that might undermine his Lord of the Manor status quo.
Everyone makes mistakes, yes — especially on a show that tears through plot and history, skipping whole years between episodes. The financial escapades are Lord Grantham's contribution to the story machine, and his conservatism makes him the foil for modern progress. Lord Grantham is meant to be a critique of the male English aristocracy, and Downton is very keen on using him to show the failures of primogeniture and class society. Except, in typical Downton fashion, Fellowes has made Lord Grantham's personal failures so absurd and buffoonish — he throws temper tantrums, for God's sake — that it seems less like historical significance and more like a writer shoveling plot faster than he can handle it. The patriarchy is a problem, but so is Lord Grantham's stupidity.
So Bates stays on at Downton, even though he pisses all the other servants off and — murderer or not — gets the whole household mixed up in some questionable business with rat poison and blackmail. Thomas and O'Brien bicker and plot against Bates, because Lord Grantham gave him the job and respect they (or Thomas, anyway) wanted. Poor Edith gets jilted at the altar (just imagine if Lord Grantham had been nice to Sir Anthony Strallan. He would have never have run). Sad, unloved young women are killed off by the Spanish flu so that Lord Grantham's business dealings can be solved tidily, but not before Grantham fusses and whines about the practical changes he must make when accepting the new money. And, as his own wife very harshly points out, his daughter dies during childbirth because of negligent medical care — medical care that Lord Grantham insisted on, over his family's objections.
He feels terrible about this. He feels terrible about a lot of things, actually, and a woman usually helps him to see the error of his ways. Lord Grantham is not a monster; he's just really bad at being Lord Grantham, and sort of insufferable when he's called out on it. He is supposed to be the protector of the house, but instead he is a walking wrecking ball, causing messes upstairs and down. It is time for Lord Grantham to stop ruining Downton. Or at least to take a business class.