His library is pointlessly overcomplicated, barely readable, and still has no type checking.
A library does not need to be readable or simple. Why do you think it does? A tutorial should be. A demo should be. A library? Nope. I don't understand why you think otherwise.
There's something I don't like about the first example:
turf/Enter(mob/m) m.loc = locate(4, 30, 1)
It seems weird to start off showing the wrong way to do something. Maybe the reader wouldn't have made that mistake. There's nothing wrong with showing a naive approach and working towards some goal, but this starting point seems deliberately bad.
I realize it was taken from an actual post, but unless I'm missing something I don't think this is a terribly common mistake. If you had used Entered() in that example, you'd still have a lot to say to explain how it could be improved.
People do seem to confuse Enter() and Entered() a lot though. Another thing I've noticed is that a lot of people try to use usr in them instead of using arguments and asserting the argument's type.
*cough cough* Really?
He did over do the comments a bit, but I really don't see how its over complicated.
It's actually extremely simple.