I honestly would like it more if they didn't sing the way they do. I know they can't help where they're from or their social class, but still, it's annoying. I also find the lyrics can wallow in self-pity a bit, even when they're done in a humorous way. And 'the four chords' get to me after a while; I'm not even sure it's because of being repetetive, I like lots of repetetive music, I think it's just the chords aren't very exciting in the first place, always so happy and major-key. But as I say, it's the vocals that are my main problem.
I can see the influence on lots, obviously, but... it's just not the same. Which is good for them, why would they want to spend a whole career just being rip-offs, but for me the vocals sound whinier, and the guitars tend to sound more... airbrushed I guessed, I can't quite describe it. Doesn't strike me the same way.