Desdichado
Hero
No, that's not true. Lord Byron was a celebrity of exactly the fashion you're talking about over a hundred years earlier. He may have been the first person to be "famous for being famous" but there was a hardly a hundred year gap between the next one.By 1950 the geeks had undermined themselves by creating a diseminatable visual arts culture, spawning the modern celebrity culture and creating 'fame' as we now it. Although there are great players before Babe Ruth, prior to the Babe Ruth era few people could follow the exploits of a great athelete. And, I think you underestimate the celebrity status of Albert Einstein.
I think you're overly romanticizing the early 20th century if you think kids routinely thought of scientists as celebrities.