I agree in theory but in practice, it's not always the full amount but you get things like BofA deducting $12bn pre-tax from their $17bn mortgage settlement[1] or JPMorgan able to deduct a large amount of their $13bn fine[2]. There is always a loophole somewhere.

[1]http://www.forbes.com/sites/robertwood/2014/08/21/bofa-grabs... [2]http://www.nytimes.com/2015/04/24/business/dealbook/deutsche... [3]http://www.newsweek.com/2014/11/07/giant-penalties-are-giant...