Funny, my editor usage is different, so I prefer dashes for the exact reason you don't. I use opt+(shift)+arrow keys to navigate and select words instead of mouse doubleclick.
camelCase and under_scores both select the full string as a word. But if you throw some-dashes-in-there, and you're using the keyboard, it's super fast to select just the bits of the value you want. Without the dash, you have the select a character level to modify aspects of the string, which is fairly fiddly for being such a common task.
A simple example of this being awesomely quick is adding a pre/postfix to values, eg:
camelCase and under_scores both select the full string as a word. But if you throw some-dashes-in-there, and you're using the keyboard, it's super fast to select just the bits of the value you want. Without the dash, you have the select a character level to modify aspects of the string, which is fairly fiddly for being such a common task.
A simple example of this being awesomely quick is adding a pre/postfix to values, eg:
@color-link @color-link-hover @color-link-active