When it results in a strong degree of genetic isolation, as described in the article you failed to understand.
The fact that it is still "corn" is no more relevant than the fact that there are hundreds of thousands of distinct species of beetles, of wildly different types and lifestyles, produced by "beetles producing beetles". Speciation is the production of new species, only a moron insists that *has* to jump entire higher taxa or it doesn't "count"...
Try to learn some science before you attempt to critique it, you're just making a complete fool of yourself.
No, only a moron claims a new species when it is otherwise identifiable readily as the same thing. Variation within the pre-existing genetics isn't speciation - it is merely variation. And when isolation produces something that can't interbreed, that's a loss, not a gain. But, then you know that.
Corn producing corn.. . 'go ahead, laugh.. it's funny' -edward scissorhands