EGO, Why?

Dear God,
I had a question to ask from you.
Why do people get angry.
I really fail to understand why does this happen. I am not saying that you should not feel bad about something that happens to you or you should not stand for the rights if you or someone else is getting deprived of in the course of this lifetime.
My question is what was the need of creating such a mechanism in the body that as soon as we get angry our blood pressure pops up and we start behaving violently. Soon our talking pitch changes and we start speaking foul or insulting words. Is this helping any one? Not only this I do not know what type of stupid mechanism you have created that when a person gets angry his processing power reduces whereas his memory power increases(Obviously he starts plucking out old dug matters and also remembers all the replies of that conversation for his life).
And then emerges the most disturbing human emotion created by you ever on earth (just like missiles and weapons invented by us), EGO. I mean what was the use of creating such a thing? If Steve Jobs and Bill Gates were good friends and has similar futuristic view towards technology, why could not they work together, I'm sure we would have been sitting on a Windows 100 or iMac 99 today itself. Of course there would have been creative differences but they were irreconcilable just because of your good creation i.e. EGO. Why couldn't America, Russia and Japan together work and use the whole money and expertise of theirs to make this world a better place to live in? Just because of EGO. They fought and mankind was slaughtered on streets to satisfy the ego of the attacker.
Why Romney, Bush and Obama are not able to sit together and work on the issues of the world ? Is it necessary to see only one to emerge as the President. Why cant the whole world be the President of the country called The United States Of The Earth.
There is a lot more to ask but as you know I also have other commitments to fulfill. Will enquire further some other day for the. But please prepare a reply till then.