Hmm I'm not sure about this, my job involves both UI design and front-end development. I like to keep my sketch files rough and ready, I never bother organising my layers, as I feel that spending time polishing them is a waste of time.
However when it comes to front-end code I try to organise it in meticulous detail. I don't work in a very large team though.
I kind of feel like the article is saying that all designers should have super tidy desks (and beards). Of course some courtesy is required when working with others but it's not a one rule fits all situation.
This article is everything I've ever had to say on the subject matter. For me, it's a basic matter of courtesy. Most importantly, I'm being courteous to my future self! Who knows when I'm going to reopen a design file - it may be months, if not years from now! I'll only be able to completely understand the contents if I've made organization part of the process of creation/curation. By keeping this part of your design method, you'll be making the collaborative environment around you much simpler to navigate.
Yesss, thank you! This is one of the biggest reasons to care, indeed.