You can view a programming language like a fighting weapon ( although I don't promote violence ). If the enemy is right in front of you, you may kill it easier

You can view a programming language like a fighting weapon ( although I don't promote violence ). If the enemy is right in front of you, you may kill it easier with a sword then with a nunchaku. But if he is around the corner, you may have better chances with the nunchaku. Or if he's at a distance you may use shuriken. One weapon can't offer all benefits, because it becomes impractical or dangerous. The reason why an OOP language doesn't let you have functions outside a class, may be the same with why you don't have blades on a nunchaku. You may hurt yourself. One needs to understand the strenghts and weaknesess of each weapon, and when it's better to use it.