The truth is because the areas that have apparently been hit worst are areas of deprivation...
Areas where the density of housing is greatest and thus less chance of isolation...
But maybe you could tell us why there are countries which have higher populations of 'certain cultures' but have lower rates of infection?
I have had the misfortune to have had to do some work over the last few weeks in Oldham, Rochdale, and the holes around there, and I can confirm that social distance is not being closely followed. It's business as usual, from what I've witnessed.
One particular instance on Monday was the bloke who just stopped his car in the middle of the road, to hold a shouted conversation with some friends ( a group of adult males hanging around outside some shops). No regard for anyone else, none of them.