They're certainly suspicious: all across the country, high street retailers are going bust, and yet somehow all these barbershops, nail salons, takeaway joints etc are staying in business, able to afford prime commercial real estate even though you never see anyone in there getting their hair cut or their nails done.
I don't know why the Turks in particular are being singled out, but that's the meme. The "American Candy Stores" in London are another famous example.
