[smoldesu]

There's still a number of prominent examples of chemical terrorist attacks, but they're mostly arranged by larger groups rather than 2 angry 4channers. Aum Shinrikyo injured hundreds in their sarin gas attacks, and the Rajneeshee bioterror attack left hundreds sick and dozens hospitalized.

The reason we don't see more of this is pretty straightforward. Although we have active imaginations, the majority of people carrying out these attacks are not Walter White. It takes organizational power to pull off an attack like that.