It's somewhat shocking that people write like this nearly everywhere. Tech sites and even many astronomy sites are no exception (e.g., Wired or Astronomy Now).
I think it's more generational than anything, as far as informal discussion goes. I don't use it, but I sometimes get called out by people older than me for using other abbreviations, like the typical internet stuff (fwiw, imo, etc.). I've even been criticized for using contractions in some settings, even though nobody under 40 cares about that (fortunately, consensus even in academic writing is moving towards "contractions are ok"). Not sure "n e 1" will go that way, but I can't say I care that much either way.
It's basically the bit.ly links of English: annoying in some ways that they didn't just write the normal thing out, and also annoying that stupid length restrictions like those of SMS and Twitter are encouraging both of them, but I'll live.
