David Mumford posted an obituary for Grothendieck that he and Tate were asked to write for Nature, which rejected it for being too technical.
I'm kind of conflicted about this. On the one hand, it really is too technical: it speeds through some very non-obvious ideas, using words that aren't terribly familiar to non-mathematicians. Overall, I think Steven Landsburg's piece does a much better job of elucidating the heart of Grothendieck's work in an understandable way. Mumford and Tate are both terrific mathematical expositors, but that doesn't necessarily translate to writing for a broader audience.
On the other hand, Mumford and Tate had a near-impossible task. Unlike Landsburg, they presumably had a tight word limit in which to tell the story of both Grothendieck and his mathematics. And the bones of what they wrote was quite good given the circumstances: I think a talented editor could have massaged their piece into something really great. We don't know the whole story here; perhaps some edits were suggested that Mumford and Tate refused to approve. Regardless, it is disappointing that Nature was unable to publish something substantial about Grothendieck.
I think Mumford was expecting too much from Nature. It's a relic of the crumbling old media regime, far too concerned with its own image to take a risk on something that might make its readers uncomfortable. My suggestion to Mumford and Tate would be to resubmit to BuzzFeed. It might get a few "WTF"s, but it will probably receive more exposure than it would have in Nature, and they'll certainly have a much better editorial experience.