There is nothing like innocent or guilty in civil lawsuit.

In a civil lawsuit you can only be find liable or not liable.

You can only settle in a civil lawsuit and the reason to do so is very simple. It's cheaper and faster.

It just isn't worth it to fight the lawsuit. The damage to your reputation might not recover even if you win the lawsuit. Even if you can prove defamation you can only get money if the other party have it. So you are most likely not going to get much from them.

So rich people and companies will rather pay you the 10% or so they would have spend on lawyers to have you go away.