Quite a few people here have a lazy attitude towards the dentist and orthodontist, mainly because until 19 years old in the UK it is free! Things are changing however, you see more and more adults with braces and adverts for Invisalign (I hate it) and 6 month smiles abound.
My parter has wonderful braces, she isn't English however
I think it is an unfair stereotype, the 'worst' teeth I've seen would have to be in North Africa (sugary diet and lack of dentists?)