Plenty of people hate Mumford & Sons. The biggest reason is because they're so popular. It's difficult to hate something you've never heard of.
But, many haters have gotten specific and the band has had enough. In particular, the hate is strong in Mumford's native country of England. Many have taken shots at the fact that British Prime Minister David Cameron is a fan. Winston Marshall told Q, "There's probably worse people who like our music. Well I dunno [laughs]. What's more annoying is to be associated with any political party, particularly if you don't like those political parties."
Marshall adds, "As a band, I don't think we've ever talked about politics. I wouldn't say I'd know what any of these three would vote in an election."
Marshall also takes issue with the "reverse snobbiness" in England. He says that one of the reasons he loves the United States, because, "There we're classless."