Funnily enough we try to cultivate everything we like, so in a roundabout way they were successful.

Nicotine, THC, and cocaine are also insecticides. And psilocybin might be an insect repellent.

Thanks poison!

The best bit about the mint and chocolate thing is that chocolate is also poison, so we spice up our poison with more poison.

All valid Points. But also, humans: i will care for this plant and create huge fields where you can live prosper and in peace. We kill everything who comes near you and try to harm you. And we will ensure you will live forever. You dont need birds who shit your seeds out.

Those plants domesticared us!

Basically humans will have sex with you, eat you, or make you a pet.

Sometimes more than one.

Tbf, this has proven to be extremely effective: Just think of how many tobacco or chili plants are grown today! Domestication really is a two-way-street

Would aliens actually be weirded out by this quality of humans?

I feel like any sufficiently intelligent species living on a planet will have some degree of biodiversity on said planet. And the chances of something being made to be a poison/deterrent for creatures other than the intelligent species is probably a large one, because it's pretty hard for plants and animals to make a poison/deterrent that kills everything without also killing itself. So if there is a gap for itself, there is a gap for other life to coexist with the toxin. And that's before accounting for the fact that something can be safe at low levels, provide benefits/stimulation/good feels at low levels, and toxic at high levels.

So I'd think it would be pretty natural for intelligent life to consume things that are harmful to huge swaths of other creatures.

Sometimes, when a fruit or seed isn't toxic enough for our taste, we make it liquid then make it ferment or age until some of its sugar turns into the deliciously neurotoxic ethanol.

Don't forget...

Yeast: oh man I love sugars so much, I just wish they didn't make me shit so bad.

Humans: dude this stuff is fucking awesome!

I evolutionary terms being edible to humans is quite useful.

TBF, life's objective is to reproduce and keep its genetic materials continuing on. Even if humans propagate and consume said plant because they find it desirable, that is still a success for the plant. So even if it has toxic caffeine or fiery capsaicin to deter some pests and humans find it enjoyable, the plant wins.

They just want to propagate. The best chance a plant has to do that is by being tasty or useful to humans so we cultivate them.

Caffeine is poisonous to us too, so I think it's more accurate to say that humans enjoy the side effects of that particular neurotoxin. It's generally not possible for someone healthy to drink enough coffee to die, but they sell pure caffeine (for research) and even seemingly small amounts of that will kill a person.

Rhubarb: most of me is poison. The rest of me is kind of bitter.

Humans: Hold my pie crust.

People who have accidentally eaten death cap mushrooms (amanita phalloides for the autists out there) say that it's fucking delicious (before their liver shuts down). Rabbits can eat them without problems. So if we use rabbit genes, we can crispr cas 9 our way to a good meal.

Is they plant that's made into cocaine in this same category?

Poppies kill things?

Aliens would extract our bile and earwax.