Because they can! It was “buyer” 

 https://external-content.duckduckgo.com/iu/?u=http%3A%2F%2Fimages.fineartamerica.com%2Fimages-medium-large-5%2Fbayer-company-sells-heroin-around-1900-merton-allen.jpg&f=1&nofb=1&ipt=bcadb66f526172b4c869e7e8b1cffef3571329a18568d140cdb49d971373a244&ipo=images 

 Because Monsanto holds some patents that are believed to be valuable.  

 GMO?