C'mon let's not beat the poster to death? On first glance a subject that could invoke the type of reaction it has. But is there a rational side to it?

How about opium or grass? Again arms up in horror no doubt. But think of Coleridge, Shelley, Poe to name three. Was their perception/ability heightened by the use of narcotics. Or would they have been infinitely better without them. Truth is we don't know.

But there are probably some folks who can take either and function more than adequately. And some who will become a slave to the drug.
Crack though I can find no positives for, highly addictive and usually mixed with other substances that increase it's damaging effects.