If one has a directory which has many subdirectories, all the folders are shown first. That's perfectly ok. 

But to more easily find the start of the files in the listing, it would be beneficial to show all the directories e.g. on a light yellow background (e.g. #ffff40).

Of course it would be even better to let one chose the colours of the text and the background separately for directories, files and links (and possibly even more categories like hidden files and so on).