Discrepancy between actual code structure and indentation is susceptible to diagnosis by machine. That's the beauty of having a bit of redundancy in the representation.
Recent GCC now has a warning for indentation that doesn't match code structure. (Had to recently patch a breakage in GNU Binutils in an embedded distro due to this being a -Werror).
The point is with lisp you can automatically and unambiguously parse and format code regardless of whitespace. Giving that up in favor of whitespace sensitive languages has real world drawbacks, no matter how many "no true python programmer" arguments you make.
I worked on Quartz for a few tears, that's over 10 million lines of Python code and many thousands of commits per day. If concerns like that really were anything more than nitpicking, projects like that would know about it.