Teachers can't punctuate, and why it should worry you...

Language is fluid, and besides, it makes sense to add the 's possessive marker to it. It's the way it used to be written.

Oops. I'm sure you'll find lots of other grammar and spelling errors.

The problem was not so much with spelling as it was with the aggressiveness of this intro.

Beyond the aggressiveness, the idea that TL;DR is bad or impossible is disputable. Everything can be TL;DRed, as long as it has a point. And in any case it's bad practice to "bury the lead".

Not to mention the fact that aleph isn't anything. The alephs are indexed by ordinals, the smallest being aleph_0.

Because of this mistake, I shall dismiss all arguments made in the blog post.

And you're probably wise in doing that.