I worked in Python for a while, and once you have a production bug because the indentation shifted around on one line when you moved some code around, you start to get really cautious and nervous every time you cut-and-paste. I much prefer C++ and Java now, where I can just paste and reformat without fear.

(I still use Python, and I'm still going to try Nim some day. Syntactic whitespace is a pain, and, in my opinion, a bad design decision, but it isn't everything.)