Why did everyone go off-topic 
Because we are in that section
General off-topic Rules / regulations :
Despite the fact that the board is called "Off-Topic Corner", this doesn't allow you to go Off-Topic while replying to a thread. Make sure to stay On-Topic as much as possible.
You do know post counts don't matter here right?
So if anybody really has nothing to do, can just go as much as offtopic in this section as he wants.
That rule corresponds to posts that are just random and simply counter-intuitive to one's thread.