What's a better word to use instead of "nicheification"?
As suggested in the title of the article, "specialization".
If you spell it nichification, you do find it in some dictionaries. The author may have been relying on spell checkers, and I suspect even the correct version wasn't on his spell checker.
The author puts it in quotes in his first use (second paragraph) to indicate that it is a word that he has made up. It appears to mean a focus on niche skills rather than competent learning abilities.
A more generally used term that could have been substituted might be niche skills.