The last thing I want is an option for this. My gosh, imagine the amount of options you would end up with if every single design choice was turned into an option. Who in the world would like that many options.
I'm happy to just have a design team work on whatever they think looks better and works best for the user experience, and implement it after some rounds of public review and testing. This looks neat enough to me - slightly less cluttered than what my current Nautilus window looks like while maintaining the same functionality.