Long before Geoff Johns became a professional comic book writer, the idea that Barry Allen might have influenced the direction of the Speed Force was a published concept. In SECRET ORIGINS ANNUAL # 2, Barry *literally* (at the time of his death in COIE) became the lightning bolt that had given him superspeed years earlier (e.g. Barry was the cause of his own origin as the Flash, though he was unaware of it). Later, it was heavily implied that Barry might also have directed the lightning bolt that "chose" Wally to also receive the superspeed (it wasn't a coincidence that Wally experienced the same lightning/chemical accident that Barry had). Even the lightning bolt that stunned Reverse Flash and reinvigorated Wally in THE RETURN OF BARRY ALLEN storyline is implied to have been a noncorporeal manifestation of Barry.
The only possible retcon that FLASH: REBIRTH introduced is the idea that Barry was also somehow responsible for Jay's gaining superspeed in the Golden Age, but I don't think that's what Jay actually meant (granted, it was odd and ill-fitting dialogue). Barry certainly didn't make Jay the Flash in any sense of the word, but he did reanimate Jay's career after years of dormancy.
FLASH: REBIRTH had its flaws, and if I had written it, I'd have told a different story...but let's not blame the character (Barry Allen) for the flaws of that storyline. Disturbingly, many readers fall into that mental trap that it's BARRY's fault that he was in a dubiously plotted story, and that that one poor story tarnishes everything he stood and stands for. These characters are not so fragile that they can't survive a bad story or two.
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