People leaving games after 15-20 minutes

It is just sad. I want to play League of Legends after a long day to relax, and then just after 20 minutes our inhibitor implodes because of some douches that think it is fun to give up, even though you're clearly winning... It just pisses me off. I want that something is done about that, because you can't seem to even get one normal game done before someone thinks it's an good idea to just crush your hopes and dreams of a win and put them inside an incinerator and stomp on the ashes after that.