It's such a subjective statement because the word 'writer' is such a broad term. For me he is the greatest lyricist in the history of popular music. yes i know there are more lauded writers such as Dylan etc and I know there have been lyricists who have sold a lot more records and I know Morrissey had written his fair share of clunkers over the years but as Noel Gallagher once put it, 'whatever you put down in a lyric to define your love or hate for anyone he'll do it one better because he's the best lyricist that I've ever read.'
Of course it's simply an opinion and like an arsehole everyone's got one, but for ME he remains untouched as a lyricist. Yet equally there is a 13 year old girl out there that will tell you that the words of One Direction songs mean more than life itself. There is no right or wrong.