I feel that the main point still stands, though. Saying that Python doesn't have a whitespace problem because you can send the code through a tool that detects whitespace-related problems still acknowledges the existence of said problem.
Well, in C the visual indentation and the meaning of the code (given by {}) can diverge. That's even worse, and happens in practice. Many style guidelines for C have evolved specifically to address that problem with 'the language itself'.
The compiler doesn't check your indentation at all. (OK, not true, these days you get warnings for misleading indentation.) But here's an example of misleading indentation in C:
if(some condition)
do something; {
do something else;
}
do another thing;
You can stretch 'some condition' out over multiple lines and have some more parents inside of it, to make it more confusing.
Not necessarily. In practice, in C-as-actually-used people (should) set up linters and formatters, so that you can rely on indentation.
When programming, this means that you can behave as if both curly braces and indentation are significant, and you get an error when they are out-of-sync.
I think its more of an tooling issue. If your editor / diff viewer cant differentiate between different whitespaces get a better one. Also if you want to ensure some function isnt in local scope etc just test it.