From my Dota experience, usually the hostility is between teammates. Because League partners 5 people together, mistakes and bad play from your teammates can ha

From my Dota experience, usually the hostility is between teammates. Because League partners 5 people together, mistakes and bad play from your teammates can have negative impact on your hero and this can be quite frustrating. Over-extensions from a team mate can lead to your hero also dying as you try to save your buddy. It is also easy to blame your teammates when you make a mistake.