Why is Rage called RAGE? Why did they name it so, I read a couple of interviews and even searched in this forum but I couldn't find anything?

I don't know, but id usually chooses short easy to remember names with some dark undertones. I guess its good from a marketing standpoint, it sticks in people's minds better than Something Something Generic: The Long Subtitle

rage quit sure when John Carmack tell for sure where it came that word, do not worry you will know later.

Yea they usually have short names but each name has some story behind it. Like we saw in the history of id software videos, Doom was named after if i'm not mistaken a dialog that tom cruise said. Quake was from D&D.

Maybe they got the name from the saying, 'Road Rage'.... since there's racing and vehicles n stuff. Other than that I never read what or where they came up with the name..