Python presented me with one insurmountable cognitive hurdle, and that's what drove me to Ruby: whitespace scoping. That single misfeature in Python is enough to keep me from ever using it in my own projects.
The compiler/interpreter should work for me, not force me to work for the compiler/interpreter. (And no, there's not always preferably one way to do things, which is an attitude I can't stand.)
It's not an argument: it's why I don't use Python. No argument here, and nothing anyone says will convince me that the Python way is the right way at all.
And yes, I can easily argue for non-indented code for certain circumstances (print-debugging outdented so that it's more obvious to the eye when you're cleaning up the binary search prints that are surrounding your bug). Python doesn't allow those circumstances; it also doesn't easily allow for nicely embedded Python in templates.
There are definitely cases where indentation as syntax is the wrong choice, and my use cases tend to hit those. Thus, I don't use Python. If someone else find this misfeature to be a security blanket? More power to them. But not me.
The compiler/interpreter should work for me, not force me to work for the compiler/interpreter. (And no, there's not always preferably one way to do things, which is an attitude I can't stand.)