Text and source code in a programming language are different things. Most lines in source code do not fill line from start to end. And there are a lot of almost empty lines (in terms of count of non-space characters). It is easy to navigate through this by eyes. But when you got a rectangle filled with characters it is much easier to get lost.
> Word-wrapping is a property of the text. And the tool you use to visualize things cannot know. End result: you do word-wrapping at the only stage where you can do it, namely when writing it. Not when showing it.[1]