Soaps never seem to recognise that the UK is a class-bound society, and sacrifice realism to keeping to the salary budget.
Ken and Deirdre, Daniel and everyone, Mike and Linda, Sean and the dentist, Kat Slater and Doctor Truman in Eastenders, the list goes on. Yes, of course in 'real life' there are couples from different backgrounds who have successful relationships, but they have to have something in common to make it work.
In Soapland it seems as though everyone just settles for staying within the pool of very local people of roughly the same age, regardless of the fact that they are very different people.