I assume you mean the poison garden at The Alnwick Garden in Northumberland. Yes it is a bit of a gimmick but I don't know of many other gardens which feature these types of plants.
As an admin of a plant group on Facebook I'm well aware of the many hysterical over-reactions to a lot of toxic plants. I wonder where people imagine natural toxins come from?
Ricin is a very dangerous poison, but not any reason not to grow Ricinus plants IMO.
As Sally says, the contents of most kitchen cupboards or bathroom cabinets are much more dangerous than your garden.
