Helen Leach, an anthropologist at the University of Otago in New Zealand, has traced unflattering remarks about cilantro flavor and the bug etymology — not endorsed by modern dictionaries — back to English garden books and French farming books from around 1600, when medieval dishes had fallen out of fashion. She suggests that cilantro was disparaged as part of a general effort to define the new European table against the flavors of the old.
But there is a reason why some people say it smells like soap to them.
Soaps are made by fragmenting fat molecules with strongly alkaline lye or its equivalent, and aldehydes are a byproduct of this process, as they are when oxygen in the air attacks the fats and oils in cosmetics. And many bugs make strong-smelling, aldehyde-rich body fluids to attract or repel other creatures.
I like cilantro well enough, but to me stink bugs smell like over-ripe apples. In the early winter when there are fresh-picked apples in the house and stink bugs have infiltrated the walls as well, it can get confusing as to which is which.
Wikipedia explains stink-bug aldehydes.