I dunno. Maybe the joke is spot on. Sure we can chicken-and-egg the problem, but someone has to be the first to make scientific discoveries just as much as reach new heights in poetry. And we surely have enough known examples of luminaries who had absolutely horrendous parents or teachers or life circumstances. We don't have great records about the historical Shakespeare, and I don't dismiss your PoV out of hand, but I am not sure it's totally correct either. We have to leave room for natural genius and insight.