I was surprised when reading The Sense of Style by Pinker (not a book I would recommend incidentally) that the use of 'they' as a generic pronoun was still considered controversial. Pinker opts to alternate his chapters with he, then she, then he again – he explains this is to avoid the issue of having to otherwise use he/she type constructs. Had he used 'they', I would've never thought anything of it. Maybe it's a geographical thing?