It's all in your own heads - if you agree with parameters of 1954, a definition which was written when times were different - i.e. no wide - scale Tele (in the UK ), no mass media etc.etc. then you limit yourselves.
Stop beating our selves-up. We're all old enough to know whether we as individuals consider The Wild Rover , or Streets of London is a folk song - it's in our own minds.
I personally, would be happy never again to play either song again in my lifetime , however in those family , friendly gatherings, which one attends from time to to , some arsehole always expects because I am a "folksinger" and I have them both complete wit Kumbaya -which they learned at Scout camp or the female version of it.
Bad examples you might say , but, I know of plenty of people who have been put off Folk music for life by a badly rendered Watercress-o.
Just enjoy it and stop putting fucking labels on it .