It's very easy: some ppl use tabs and the editing looks different to the final display.

Making that consistent° will spare us from seeing some ugly code.

off topic

If you want to forbid tabs altogether, you or others are free to implement² an untabify feature like in emacs and many other IDEs.

But that's another discussion and step. And it won't make misformatted code better readable. Especially as long as the input textarea looks different to the final rendering (sic).

Regarding perltiy: I'm looking forward to see the patch³ to integrate this here.

°) should be easy

²) not that easy, but feasable

³) LOL