Could being a toxic or venemous creature be bad for survivability of a species in the long term if smarter creatures discover you’re lethal and thus become determined to kill your kind on sight?
Perhaps interesting; https://pubmed.ncbi.nlm.nih.gov/34816428/ (Still need to read it)
I am not aware of any species besides humans that do this, though.
Same deal with spiders, they're obligate carnivores. If there are spiders around, that's because there are other bugs about.
Honestly I understand wolf culls a lot more. I don't agree with them, but I understand the rational motive of people who have livestock, pets, or even children.