Compairing Erdos with other Mathematicians is a really bad idea. I believe he would have been an outlier without drugs. Its like comparing Lance Armstrong with other racers.
That was indeed the parents point, I believe. Armstrong was still an outlier, and the drugs allowed him to take that further. Even without them he would've been one of the best (assuming all things being equal and no one else has access either).
Still, a mathematician improving vastly on drugs can be a net benefit for society since the work done stays. A cyclist.. I don't see it. Not that I'm advocating for drugs in general here.
