It's probably because in algol derived languages -- when you encounter parentheses, something weird is happening -- something you've got to put extra thought in

It's probably because in algol derived languages -- when you encounter parentheses, something weird is happening -- something you've got to put extra thought into. Maybe the ordering of something is being forced. Maybe something else is going on, but whatever it is requires more thought than things that are parentheses free. So you look at Lisp and your brain locks up the brakes, with "WTF is going on here??? I'm out".