A summary for those of you who don't have time to wade through poorly-written articles: PageRank, like almost all machine-learning algorithms, has some knobs which you can tweak to get various results. This guy, as an algebraic topologist, hates knobs and calls that "bad math."

>>PageRank, like almost all machine-learning algorithms, has some knobs which you can tweak to get various results.

PageRank is a machine-learning algorithm?

"You can tweak" means Google can tweak not the user...

> PageRank is a machine-learning algorithm?

PageRank is the definition of a machine-learning algorithm.

Omitting "(mathematically)" from the title seems misleading.

Updated.