The fact that you don't hear Bertholy mentioned in the forums you noted does not mean that those same instructors you do hear mentioned do not know of Bertholy or speak of him themselves. At least one such has made money promoting a training aid that 'appropriates' one of Bertholy's terms. Another one such spent a fair amount of time learning under Bertholy before becomming a 'name' professional instructor.
Still these are just individual proof points. More relevant to Bertholy's level of visibility with top teaching pros today is the fact that he taught many of them through his role with the PGA.
Fame with the 'common folk' is not equivalent to recognition in the professional community or contribution.