So a rising IQ lifts all boats? You're hoping the wealth will trickle down?
(Myself, I'm selfish. At my ~130 IQ, most of the world would be eligible to take this drug, utterly crushing my market value; and since at best they would reach 140, I can't appeal to any arguments like 'but the emsmartened masses will cure aging! Better to be an immortal janitor than a dying tycoon.' So I wouldn't be happy about it, even though abstractly I know it'd probably be a very good thing for humanity.)
But aren't smart people just more fun to be around? Superiority is boring.
There was some talk here about height taxes, but there's a better solution - redefine shortness as a treatable condition and use HGH to cure it. They even got FDA on board with that, at least for 1.2% shortest people.
Unsatisfactory sexual performance became a treatable condition with Viagra. Depression and hyperactivity became treatable conditions with SSRIs. Being ugly is already almost considered a treatable condition, at least one can get that impression from cosmetic surgery ads. Being overweight is universally considered an illness, even though we don't have too many effective treatment options (surgery is unpopular, and effective drugs like fen-phen and ECA are not officially prescribed any more). If we ever figure out how to increase IQ, you can be certain low IQ will be considered a treatable condition too. Almost everything undesirable gets redefined as an illness as soon as an effective way to fix it is developed.
I welcome these changes. Yes, redefining large parts of normal human variability as illness is a lie, but if that's what society needs to work around its taboos against human enhancement, so be it.