If anyone was curious about the Eva/Warhammer one; the exact link is http://www.fanfiction.net/s/3886999/5/Shinji_and_Warhammer40k
(I’m reading it through and while I’m much more familiar with Eva than Warhammer, it’s definitely better than most fanfiction.)
I don’t think it’s either. Consider the many blog postings and informal essays—often on academic topics—which begin or otherwise include a narrative along the lines of ‘so I was working on X and I ran into an interesting problem/a strange thought popped up, and I began looking into it...’ They’re interesting (at least to me), and common.
So I think the reason we don’t see it is that A) it looks biased if your Op-ed on, say, the latest bailout goes ‘So I was watching Fox News and I heard what those tax-and-spend liberals were planning this time...’, so that’s incentive to avoid many origin stories; and B) it’s seen as too personal and informal. Academic papers are supposed to be dry, timeless, and rigorous. It would be seen as in bad taste if Newton’s Principia had opened with an anecdote about a summer day out in the orchard.