Acai berry is ok, but Bitcoin is bad?
Someone, especially a someone with a smartphone and poor impulse control, might lose $200K investing in a cryptocurrency. The sort of person who has that money to lose is either retired or reasonably wealthy, and therefore has the time or self-advocation skill to have an incremental influence on legislation or regulation.
In general, health supplements, miracle berries, etc. sit on dubious scientific ground: many have either not been extensively studied, or have been studied and shown to have no discernible effect (good or bad). The assertion here is not that açaí itself is bad per se, but that it is marketed as being healthy with little or no scientific evidence to back that up - and therefore that people are being convinced to waste their money through deceptive marketing, in that they imagine themselves to be getting a health benefit that likely does not exist.
Is this commonly used to refer to acai berries? The only "miracle berry" I know of[1] is named for the effect on perception of flavor caused by the chemical miraculin, which is produced by the berry.
They're also extremely fun to introduce to people who have never tried them before, and I highly recommend them for your next party.