The answer is simple: The company has the Environmental Protection Agency (EPA) in its pocket, and they're all too willing to help them cover up damning evidence that their products are toxic.
The EPA is a government agency, and Monsanto knows that lots of people trust authoritative groups supposedly tasked with "protecting" us. It's been a mutually beneficial relationship over the years, with a recent piece in Bloomberg Businessweek — hardly part of the "alternative media" — breaking down the dirty details of their dealings over the years.
A recent EPA paper put forth as part of a panel in charge of reviewing the agency's stance that glyphosate doesn't cause cancer — which caused a lot of controversy among experts. In fact, eight of the 15 experts there displayed serious concerns about the agency's stance, and three others voiced concerns about the data.