As well as the researchers' patent, actually growing golden rice requires licences for a thicket of patents on the underlying technology from dozens of companie

As well as the researchers' patent, actually growing golden rice requires licences for a thicket of patents on the underlying technology from dozens of companies (and it required some wrangling to even get permission to license that patent for free since the government grants they got would usually require commercial licensing). They managed to get free licenses to those as, basically, a PR exercise - it was worth it to all those companies to do it because it let them spin opponents of their profitable products as monsters who wanted third world people to suffer. The licenses also had conditions that made them basically unusable, so if someone did miraculously manage to make golden rice viable they didn't have to worry about losing out on their cut.