Why banned?

So I'm kinda new to MPGH.
And I just have some questions.

1) Why do people get banned for getting lots of posts?
2) Why does somebody like him get banned for having over 1337 posts??
3) When is the next time I will get banned? like when I hit 1k posts?


Please answer me like this:
1) Answer
2) Answer
3) Answer

Thanks for reading this, I'm just so confused