That's because most IDEs don't have good support for web development. (I wonder what would happen if they are good for web development, would people's opinion change?)

I used Vim to modify CSS and JS but I struggled to navigate JS code because I cannot jump to the method implementation with some sort of magical shortcut key easily. This is pretty tough if I want to know why I don't get my intended result out of calling the method.

To add injury to that, I found out that I have to redo the implementation and call the method something else to describe the intent in full. I can't refactor that easily without going to the path of hell: grep, regex, sed.