I would also suggest, not many can write a (decent) Morrissey vocal melody. For all his present-day arsery, his musical contribution to those songs often gets overlooked. His odd song structure, with little regard for the conventional format, and peculiar melodies which seem somehow biologically attached to the lyrics are unlike anybody else's work. I wonder if that's why Morrissey managed to edge ahead of Marr in their solo careers: he had two unique skills, whereas Marr only had one (great though it was/is).
Spot on. There should be a whole book written about The Smiths/Morrissey/Marr from this perspective.
Marr will never be able to write songs as great as The Smiths, or Morrissey at his best, for the above reasons. He simply doesn't have the vocal skills or the lyrical talent that Morrissey has. Morrissey has demonstrated, again and again, that because of the particular skills he has, he can take a quite rudimentary and/or bland piece of music and craft a great song from it - he doesn't need great music to make a great song. Marr, on the other hand, even when working with his own promising material, is only ever going to be able to overlay a vocal that relies on cliched lyrics and conventional, derivative phrasing. Although, furthermore, there's also the fact, which I rarely ever see mentioned, that even his music has never approached the subtlety, complexity and melodic richness of early Smiths stuff - and I don't know why that is exactly: lack of inspiration perhaps, or maybe the input that John Porter and Andy Rourke had, and also the fact that a lot of his musical harmonies were laid down after Morrissey's idiosyncratic vocal melodies had gone on the track. But certainly when you see him playing live in the Smiths gigs, there's no doubting his musical genius. I suppose these days he doesn't even want to play stuff that complex, as he has to sing at the same time.