I think integration would be helped enormously if isolated incidents like this one appears to have been weren't blown up into such massive scare stories by the media.
I don't think that's a very realistic hope, even though I don't think the media actually blew this story up into a massive scare story.
The story really took off on Twitter, and in other social media, including the M&S Facebook page, and other forums like this one.
Fortunately M&S have now said that they have abandoned this policy, and that any employees who object to serving certain products at the checkout won't be put into those positions.
Why they didn't have the sense to do that in the first place beggars belief.