The b d is a classic. Apparantly children should be able to distinguish by around 7 years of age, a bright child sooner. My DS, 11, still can't and I know some adults who can't but who would not call themselves dyslexic.
I think the label is good iin that it raises awareness that not everyone sees the written word in the same way. Naturally good spellers can be very precious about it and make assumptions about others because they lack that ability. We are lucky in that computer technology can help with poor spelling but there will be times when people can't and shouldn't have to use that technology.
Spelling doesn't equate to intelligence. Many people, I believe, still think it does.
This may explain why many dyslexics are artists and architects, they naturally see things from all angles...
Interesting, also I wonder in the past if many would have gone down the art route because it was the one area where they weren't penalised?