[mdibaiee]

For me the reasoning is being able to distinguish between what needs to be wrapped, and what I would prefer not to be wrapped. In this case, code samples would preferrably not be wrapped. If I can wrap normal text manually, and keep code samples unwrapped, the client can disable wrapping entirely and see the code lines untouched.

This is possible with HTML and CSS, but not in plaintext. I think wasted space is something I can handle, but a badly wrapped code is something I dislike.

[dundarious]

This is the exact reason the Linux kernel developers require plain text emails to be pre-wrapped. You cannot leave it to the reader, because readers will always/never wrap both text+code — they cannot distinguish, and text and code have very different wrapping requirements.