Focusing on the editor won't help because then you're adding an unexpected constraint on the user.

I think I happened to experience it using kwrite, or maybe also notepad++ when I had to edit something from a non-default computer once. The point still remains that editors which /try/ to be smart and helpfully correct, convert, or automatically indent things, won't always do it the way you might have wanted. What works in one context won't work in others, and having context sensitive whitespace handling can bite you when the program isn't aware of which context it's supposed to be crafting the document in (EG when you start a new one or copy an example from the web).

"Unexpected constraint" is a very curious choice of words. In my experience, when you teach novice programmers, braces and semicolons are the unexpected constraints. Line breaks and indentation is a bit more expected to the novice programmer. ("Optional semicolons" like in JavaScript seem to be the worst of both worlds.)

Programmers with experience will expect things to behave like the languages they know. If you are experienced with Python, Haskell, or YAML, they won't seem like surprises.

Funny that Notepad++ and Kwrite have given you problems, those are usually fairly good editors and should be able to write Python / Haskell / YAML just fine. I wonder what happened to cause those problems.

I hate it when languages and formats care about whitespace beyond just whether there is some between two tokens.

Not being able to use tabs in Haskell is annoying for example. And I find having to indent stuff so it is off the page to the right to get stuff to compile unsatisfactory.

Same with YAML. I detest a format where indenting matters. It shouldn't matter.

I get that you hate Haskell, Python, and YAML. Could you explain why you are sharing this hate with everyone here? I mean, what is the point? There are lots of things I hate, but I don't revel in that hatred.