You see, this is one of those seductive little ideas that sounds like it should be true, but - I think - actually isn't. Maybe in the case of some instances of severe bigotry or prejudice, but not generally. If you find Mumford And Sons contemptible - and I hope it's a safe bet that you do - does that mean you're afraid you might secretly like them? That you recognize something of yourself in who they are and what they stand for? I dunno, maybe you do. I hope not, for your sake!
Apols for stream of consciousness:
But that's just a particular instance of the shame/contempt phenomenon, where Mumford & Sons arouses feelings of attraction that a person can't handle, and therefore they disguise the attraction as contempt for Mumford & Sons. While I think this is way more common than you believe (for objects other than Mumford & Sons), far from the only option.
Another: the object (i.e. person) has said something/behaved in a way that you find wounding/threatening/shaming on a very basic level, and you're hitting back at them because of this perceived wound (usually unintelligible to observers).
Or, nothing to do with the person/object's features, but one feels a need to 'offload' uncomfortable feelings about oneself (shame etc) onto something/someone else through contempt, simply because it's a convenient object for their scorn (maybe perceived as weak/easy target, or maybe because the contempt can be disguised as 'moral' in some way). I call bullshit on anyone who says they've not acted in a contemptuous way towards others when/because they've felt vulnerable.
Obviously you come across as contemptuous of the author in turn - fair enough. But I'm completely confused as to why this guy has got under your skin so much (rather than you just finding him mildly annoying, that is)! I'm contemptuous of things/people all the time, often for one of the above reasons, and you'd usually have no idea why I felt that contempt either.
People love to rationalise their contempts according to a supposed objective list of things that are wrong with their object of scorn, but it's never as rational as claimed. It's like the EU talking about Greece.
PS The way people hate on hipsters is a great example of all of the above. You could (a) be secretly jealous of the fun they seem to be having; (b) hate them because they remind you of people at school who ostracised you, opening up an old wound, or (c) just use them as a socially-acceptable punching bag to get rid of some unwanted feelings... I've definitely been guilty of ...all of the above. In any case, the contemptuous vitirol is often totally out of proportion to any 'rational' social-level explanation of 'why hipsters are objectively bad'. (Obviously they are scum though)
PPS I'd never knowingly listened to Mumford & Sons before today.
Thanks a lot