usually when your refused they will list more than one reason (to try and justify the refusal)

someone on here not long ago, overdrawn statements was one of the reasons, i cant remember if it was the only reason for refusal, but they owned their house outright.

they asked for reconsideration and the refusal was overturned, without going thru a long wait with an appeal

why i say you were lucky is, you need to show you have fianances that you can have quick and easy access to (property, isa's etc might not be) so your wife will not 'need recourse to public funds' and if your overdrawn how can you support your wife

anyway most of us have been in the same boat, playing the waiting game, some people waiting for many months to get good bank statements

but good you got it but not everyone will be as lucky as you, that's why I advise people, 6 bank statements and no overdrawn ones to minimize risks of refusal..