I know what you mean about it being authentic. And I might feel differently if I didn't wonder if the writers had set it there to get around having to bother casting minorities (beyond the one black family).

I grew up in rural Ireland myself and ethnic minorities were more or less invisible as well. Mind you we also didn't have many people who weren't born and bred in that area either, so realising that people often didn't come from areas in which they were living was also somewhat of a shock to me!