Fuck Monsanto et al whose business depends on shifting ludicrous amounts of the nastiest chemicals known to exist.
Checking Wikipedia, glyphosate (Roundup) is 10% of Monsanto's business, and sale of roundup-ready crops is 50%. That's 60% of Monsanto's business right there dependent on glyphosate.
I would not put glyphosate into the category of the nastiest chemicals known to exist. For that category, I'd suggest something like dioxygen difluoride (O2F2) which is just the thing if you ever had the problem of making ice explode at -200F.
Dioxygen difluoride doesn't appear to have a commercial use, probably due to its vigorous interactions with other chemicals even at low temperatures. But there's another fluoride compound, chlorine trifluoride (ClF3), which is used commercially. ClF3 is reported to ignite asbestos, as well as far more mundane materials such as glass. It also does horrible things to the human body.
Even if we limit ourselves to herbicides, there's far deadlier herbicides, such as paraquat, which is an order of magnitude more toxic, and is actually used for suicides in developing countries due to its cheapness and low fatal dose.
There are things I don't like about glyphosate and Monsanto, but lets keep things in the realm of reality, okay? Speaking of which, you may want to check the size of Monsanto relative to it's competitors.