The ninja is hiding behind the samurai, naturally.

So I don't have to be a Ninja or a Samurai to get anything out of this book? ;-) Awesome.

The title still sucks. I don't get this idea of (ninja|rockstar|etc) and it's extremely disrespectful to those that practice those disciplines.

I hope your last sentence was a joke

Not at all. The disrespect comes from the stupidity of the title and people making it. Rockstar? Ninja? Evangelist?

Really?

How about Shaolin Monk JS? Hung Ga JS? Hung Fut JS?

Is the absurdity getting through your brain yet?

And if you're talking "Evangelist," where the fuck is your church?

I think you're wrong. Unless you want all books to be called 'How to be really good at...' or equivalent, then people have to try to be original to some degree which includes using words in new contexts.

I looked up ninja (http://zillyninja.blogspot.ie/2011/02/origin-of-word-ninja.h...) and apparently it can mean "a person skilled in stealth" or "one who endures." while the ninja themselves were spies for the samurai but haven't been around for a long time (http://web-japan.org/kidsweb/explore/history/q4.html).

I guess that you'd have no problem if someone called their book 'how to become a javascript expert'. Expert comes from the latin word expertus ( past participle of experīrī to try, experience) (http://dictionary.reference.com/browse/expert?s=t) and presumably someone had to import it to english and later on someone else used it in a new unorthodox way.

BTW I looked it up and the word evangelist comes from greek and means 'bearer of good tidings', so it isn't something that has to be tied solely to religion

It's not about etymology, it's about people adopting silly phrases for common terms that already exist simply to try to appeal to emotion. Rockstar developer? Really? Would a Boy Band Developer count?

If you want to do that, go write fiction. If you're as adept at writing in the English language as Anthony Burgess or James Joyce, you can feel free to even make up words as you go along, not just new uses for existing words.