However, after reading that chapter, I really can't help thinking that you simply weren't paying any attention.

It's not just written in sarcastic tone (something that yes, could be easy to miss for many), but it's also littered with active dissuasion and explicit explanations of the pitfalls of using this style.

Examples:

> If you write like that, a developer who comes across this line and tries to understand what is the value of i is going to have a merry time. Then come to you, seeking for an answer.

> A quick read of such code becomes impossible. And when there’s a typo… Ummm… We’re stuck for long

> A fellow programmer who wants to work with elem in the second half of the function will be surprised… Only during the debugging, after examining the code they will find out that they’re working with a clone!

> First, the code becomes longer and less readable, and the second, a fellow developer may spend a long time trying to figure out what the underscores mean.

You can argue that the chapter is inappropriate, but I don't think you can reasonably argue that it's misleading.

The whole chapter is littered with clearly tongue in cheek remarks.

"A JavaScript Ninja writes code that is brilliantly mysterious. When people read such code it should induce confusion and if at all possible, fear. Clarity is for the feeble. Obviousness is overrated. Obfuscation and secrecy: that is the way of the Ninja. So, how do you become a Ninja?"

How someone interprets a tongue-in-cheek chapter could be a good litmus test of their reading comprehension, grasp on the fundamentals, and (last, but not the least) basic sense of humour. I’d hate to see it removed.

If someone takes this section literally, I would be immensely curious how they reconciled in their mind that advice with what they (supposedly) read in preceding sections.