The point isn’t whether a produce needs a hecksher, it is whether enough consumers believe it needs a hecksher, which determines whether any manufacturers determine that paying for a hecksher will produce enough marginal revenue to justify the cost of the hecksher.
This has nothing to do with halacha, or even politics, but is totally a matter of economics — at least in a capitalist system where consumers are free to choose which products they consume, and manufacturers decide what to produce in order maximize profits.
A similar debate is occuring among the goyim over natural, organic and non-GMO foods. While there are no scientific or health reasons to prefer such foods, some consumer prefer them, and some manfacturers provide them.
In a socialist system, the government would decide what you consume and how much, and how it should be made and by whom. But we are in a market economy based on consumer preferences. Live with it (and enjoy – you really don’t want a command economy).