FWIW, a counterpoint: I work in C++ (80) and Go (no line length limit) at Google and I barely even think about it. I just write code however feels natural and then run 'hg fix' before sending for review.

I would definitely not impose 80 if it were my choice but it really doesn't bother me when clang-format is set up as nicely as it is.

Probably Python should switch to the Go model, since auto-splitting python lines sounds tricky.