Sure, only minorities or inferior whites suffer from addiction to such substances - but the use of plant based mood enhancers are common across all economic and social strata.
Opium was first banned back in 1875 in San Francisco.
Probably not because the Chinese used it.
It's use probably spread to the homes of well-to-do and influential upperclass whites - and that could be a problem.
So now Kratom is seen as being just as bad as the Opium it was used to replace?