Very informative article, really like it.
If I can propose something, is more examples :)
Or at least maybe a link to some articles.
You sometimes say “don’t do it” but the reason behind this, despite out of scope of this article, could be sometimes linked.
- You have a separate section “Code examples”. If possible, could you put these examples next to the topic they demonstrate?
- You have a short section titled “To sum it up:”, could you provide some code examples to 2 points there?
- Do you know any article, maybe it is worth to link it, why: “You really don’t need it. Just let the cascade go.”
One small things from me:
You say folders structure for your pre-processed files doesn’t matter because they are combined in one CSS file, most of the time.
I would be very careful with his, if you get too many files in one directory, then introducing a separate, logical sub directory would be a good idea.
Also, there are potentially still cases, where you sometimes do not merge your CSS into one file.
For example when you have tons of extra CSS rules for one page, like product page. Maybe you don’t want to have CSS for product page loaded on every page, hence potential need for 2 CSS files.