Why have Mumford and Sons got mass appeal?

[housework]

That song is played everywhere. It's odd, folk appealing to the masses.
Is it because they've got those beards people have at the moment and went to public school?

God knows! They are hugely popular with teenagers which was a surprise ( shock) to me.

They sound like something Mike Harding plays on Radio 2

I have been brought up with folk music so I like them, but yes, I know what you mean.

The beards/public school thing carries no weight with me. I could walk past 95% of the members of the bands I like and not recognise them - I know virtually nothing about them and care even less, I just like the music I like

Because jangly jangly.

I love them.

They sound good and they have a great time playing music.

because they're bland and in offensive

I would guess that often with bands that have "mass appeal", the music isn't very different to that of other bands/artists in the same genre, but the way they are presented is different, and the emphasis is on the more accessible songs (they are a gateway drug!).

Dey iz crappy init yo,

n dubs is da bombizzle biscuit

Beats me.