Brilliant code comments, I've never seen this explained and it will come in handy.
I see so many random terrain generation posts, like it's some sort of a hard problem that's being solved on a weekly basis. This one isn't even impressive.
It's interesting to see implementations of algorithms in languages. Terrain generations is a fun problem with a few algorithms and nice visible results.
Maybe you should consider showing some stuff that you've made instead of being snarky about stuff that other people have made and shown.